Presidents have relatively fixed powers but exaggerated responsibilities, for which they can blame their predecessors. Theodore Roosevelt transformed the office into a "rhetorical presidency," and his cousin made it a "plebiscitary presidency."5 They both found that marshalling public opinion through direct communication with the electorate enhanced their ability to build political support for their agenda. Using public approval, however, has led the electorate to hold Presidents accountable for progress in areas outside their formal powers. Presidents of all stripes and parties have inevitably expanded their powers to meet their political responsibilities. They both found that marshalling public opinion through direct communication with the electorate enhanced their ability to build political support for their agenda. Using public approval, however, has led the electorate to hold Presidents accountable for progress in areas outside their formal powers. Presidents of all stripes and parties have inevitably expanded their powers to meet their political responsibilities.

PRESIDENTIAL POWER IN THE MODERN AGE.

ONE OF THE LESSONS of this book is that the Const.i.tution creates a ma.s.s of executive power that can help Presidents rise to the challenges of the modern age. This power does not ebb and flow with the political tides, but finds its origins in the very creation of the executive. The Framers rejected the legislative supremacy of the revolutionary state governments in favor of a Presidency that would be independent of Congress, elected by the people, and possessed with speed, decision, and vigor to guide the nation through war and emergency. They did not carefully define and limit the executive power, as they did the legislative, because they understood that they could not see the future.

If Congress could enact legislation that successfully antic.i.p.ated all possible circ.u.mstances that the nation might confront, or could act swiftly and decisively itself, a separate executive might be unnecessary. Those who wrote and ratified the Const.i.tution, however, viewed untrammeled legislative power with deep suspicion. More often than not, the dominant state legislatures of the Revolution had failed to organize effective executives and had fallen into interest-group politics. The Continental Congress, which had no executive or judicial branch, suffered paralysis. Erecting an independent executive, and an independent judiciary, would allow the nation to act effectively and restore balance to its political system.

Use of presidential power does not signal failure -- otherwise, Presidents like Washington, Jefferson, Jackson, Lincoln, and FDR would not merit their reputations today. Nor does executive action guarantee success. Instead, it sets the foundation for a President's ability to achieve. Our greatest Chief Executives have all vigorously exercised the powers of their office to the benefit of the nation -- establishing the independence of the executive branch, purchasing Louisiana, blocking the politicization of the national bank, winning the Civil War, entering World War II, or containing the Soviet Union -- but only in times of crisis. A branch headed by a single person, as Alexander Hamilton recognized, can act swiftly and decisively because it is not subject to the crippling decentralization of Congress. Emergencies and foreign affairs sit at the core of the purpose of the executive, and no President has successfully responded by pa.s.sively following Congress's lead and forsaking his right to independent action.

Presidents have often wielded their powers in the face of congressional silence, and sometimes they have acted contrary to Congress to advance what they perceived to be the national interest. Obviously, Presidents will find governing easier when their political party enjoys large majorities in Congress. Some scholars link the growth in the Presidency to its position as party leader, and attribute the loss of executive influence to efforts to govern through an administrative state instead.6 But even under unified government, Presidents have had to rely upon their const.i.tutional powers when acting at odds with the wishes of their legislative supporters. Jefferson over-came const.i.tutional qualms about the Louisiana Purchase; Lincoln rejected congressional Reconstruction plans; FDR tried to pack the Court and unseat leading Democrats in the South. Congress can still frustrate a President of the same party and doom him to failure, as was the case with Jimmy Carter and Herbert Hoover. Party government remains an important feature of the power of the modern Presidency, but it can act as a straightjacket just as easily as a lever. But even under unified government, Presidents have had to rely upon their const.i.tutional powers when acting at odds with the wishes of their legislative supporters. Jefferson over-came const.i.tutional qualms about the Louisiana Purchase; Lincoln rejected congressional Reconstruction plans; FDR tried to pack the Court and unseat leading Democrats in the South. Congress can still frustrate a President of the same party and doom him to failure, as was the case with Jimmy Carter and Herbert Hoover. Party government remains an important feature of the power of the modern Presidency, but it can act as a straightjacket just as easily as a lever.7 The same dynamic describes the relationship between the Presidency and the administrative state. Agencies facilitate the implementation of executive branch policy. Without the main cabinet departments, the President could not achieve priorities on finances, defense, law enforcement, or foreign policy, not to mention the broad array of decisions on economic and social issues delegated by Congress. On the other hand, the agencies create bureaucratic routines that hem in a President's ability to achieve swift change. While they are designed for rational, comprehensive planning, agencies and their processes inherently resist the ideas of a new President. The inertial weight, or even the outright opposition, of the bureaucracy -- composed, after all, of career civil servants who have their own policy interests -- is compounded by the emergence of powerful interest groups, congressional oversight committees, and a media culture focused on conflict. Presidents have responded by attempting to strengthen their control over the administrative state through their const.i.tutional powers of removal, just as Congress has sought to keep agencies within its own political orbit.

While executive power is more general and open-ended than other powers in the Const.i.tution, it is not undefined. Its general nature does not automatically subject it to congressional control, any more than the vesting of the "judicial power" in the federal courts makes judges the servants of Congress. The bulk of executive power rests in foreign affairs and national security, where it is most suited to effective action. During peacetime, the Const.i.tution limits the Presidency to enforcing the law (which includes, as the highest law, the Const.i.tution itself) and managing the executive branch. While executive power has grown throughout American history, its most vigorous use appears sporadically. Only crises and challenges call it forth.

World War II and the Cold War broke this pattern of peacetime quiet punctuated by presidential action in times of crisis. The postwar growth in presidential power is not the result of the inexorable and unwarranted aggression of an imperial executive, but America's changing place in the world and its new ambitions at home. Foreign policy has unquestionably become of vital importance to the nation. By the end of World War II, American leaders finally understood that events abroad dramatically affected the nation's security as advances in transportation, communication, and technology eliminated the distance and security that the oceans once provided. Committing to the defense of Western Europe and East Asia required the permanent mobilization of a large standing military. Containing the Soviet Union and maintaining a liberal international order based on free trade and democracy demanded the ability to exert military and diplomatic force along many dimensions. As the executive was designed to be continually "in being" and to have the leading const.i.tutional role in foreign affairs, presidential power naturally increased to match the demands on the government. What marks the postwar period as a sharp break with the past is not presidential unilateralism; rather, it is the change in circ.u.mstances that demanded executive initiative. It was not the Presidency that became imperial, it was the United States that became an empire.

Rising expectations of government prompted a corresponding jump in presidential power at home. The New Deal's goal of guaranteeing economic security demanded a ma.s.sive expansion of federal economic and social regulation. In the 1960s and 1970s, Congress broadened the role of the federal government into civil rights, the environment, consumer safety, poverty, housing, and crime. Extensive intervention called for bureaucratic resources that Congress simply does not have and would not want. Delegation to the executive branch agencies served multiple purposes. It allowed Congress to shift responsibility for decisions that are politically controversial, call for difficult choices based on technical and scientific information, and involve high but unpredictable stakes. Members of Congress could focus their limited time and energy on spending programs, earmarks, and tax breaks for const.i.tuents and interest groups who supported their reelection.8 A second lesson of this book is that the notion of an unchecked executive, wielding dictatorial powers to plunge the nation into disaster, is a myth born of Vietnam and Watergate. Congresses have always possessed ample ability to stalemate and check an executive run amok. Congress regularly ignores executive proposals for legislation, rejects nominees, and overrides vetoes. It can use its power over legislation, funding, and oversight to exercise significant control over the administrative state. There would be no agencies, no delegated powers, and no rule-making without Congress's basic decisions to create the federal bureaucracy. It can use these authorities even at the zenith of presidential power: foreign affairs. Congress can cut off war funding, shrink the military, stop economic aid, and block treaties. It used its sole control of the purse to limit the Mexican-American War and to end the Vietnam conflict, for example.

Of course, cooperation between the President and Congress on national security policy is politically desirable, but it has never been const.i.tutionally necessary. As we have seen, our greatest Presidents have, at times, acted contrary to Congress to protect the nation. It was their judgment that the Const.i.tution did not require the government to sit on its hands until both the President and Congress agreed on every particular. It is no doubt correct that requiring legislative consent would promote greater deliberation and slow down hasty decisions. But the collective-action problems that make the legislature slow bear costs, too -- costs that can become acute when national security is involved, especially in light of technological change that has made weapons swifter and vastly more destructive. Expanding the numbers involved in decision-making does not guarantee that the results will prove more accurate. Congress makes mistakes just as the executive does, and the costs of national security paralysis might outweigh any marginal decrease in errors.

Political scientists are beginning to appreciate that the model of an inst.i.tutionally weak executive cannot explain the growth of presidential power during the last half century. Recent works applying game theory to the separation of powers have recognized a large area for presidential action. According to these studies, the President will most often be able to succeed in areas where the stakes are high, the issues are complex and unpredictable, or political controversy means large portions of the electorate will disagree with any government decision. Congress has far more interest in awarding discrete benefits to const.i.tuents and supporting interest groups than in risking a serious mistake of national policy or generating political opposition. If the President acts first, Congress will have to take an affirmative step to overrule him. A presidential veto of that legislation will be sustained if more than one-third of the Senate agrees with him. Not surprisingly, legislative proposals to overrule executive orders rarely succeed.9 These approaches cannot work without a proper understanding of the President's const.i.tutional authorities. Take the effort to model the President's role in the legislative process. During the 1980s and 1990s, political scientists developed rigorous frameworks to understand the movement of legislation through Congress. In these models, the role of the President was often an afterthought, an oversight since corrected by the work of the last decade. These scholars identify the conditions in which presidential vetoes, or even the threat of a veto, will win policy concessions from Congress.10 For that variable to be significant, the President must have the power to veto legislation on policy, rather than just const.i.tutional, grounds. Without that change in the understanding of the President's veto power, his ability to influence legislation would be dramatically reduced. Scholars also observe that Presidents prevail more often in foreign affairs than any other significant area. As with the veto, this would not be possible without an understanding of the President's const.i.tutional authorities. One singular reason that the President may win more often in foreign affairs is simply that his const.i.tutional powers, and hence his freedom of action, are greater beyond the nation's borders. For that variable to be significant, the President must have the power to veto legislation on policy, rather than just const.i.tutional, grounds. Without that change in the understanding of the President's veto power, his ability to influence legislation would be dramatically reduced. Scholars also observe that Presidents prevail more often in foreign affairs than any other significant area. As with the veto, this would not be possible without an understanding of the President's const.i.tutional authorities. One singular reason that the President may win more often in foreign affairs is simply that his const.i.tutional powers, and hence his freedom of action, are greater beyond the nation's borders.

Exercise of these const.i.tutional powers does not guarantee presidential greatness or success. Progressive scholars of the first half of the last century believed that the President should the play the role of a political hero who would represent the people better than a Congress beset by special interest groups. Chief Executives would use their const.i.tutional powers to restore democracy and expand the powers of a national government that would respond to the people's wishes. But Andrew Johnson, Lyndon Johnson, and Richard Nixon demonstrated that not everyone would rise to this vision of the reformer President. Executive power does not inexorably bring progress. Const.i.tutional power may not be enough to help the President overcome the many demands and obstacles placed in his way by the modern political system, and it certainly does not prevent a President from making poor decisions.

Yet, executive power remains the wellspring of a President's ability to play a transformative political role, which remains a key distinction between the great and the merely good. Stephen Skowronek has persuasively argued that the Presidency's political authority moves in cycles. Certain Presidents are "reconstructive" -- they repudiate a vulnerable political order, often shown to be incompetent during times of crisis, and replace it with a new one. Other Presidents maintain the existing order and governing coalition, with their success declining rapidly if events have undermined the regime. A small set of Presidents come to office opposed to the existing political system, but that system is resilient, and efforts to preempt it will lead to conflict and often failure. A President's success depends on his matching his political "warrants" -- in other words, his electoral and political support -- to the circ.u.mstances of his day. According to Skowronek's retelling of presidential history, a deep structure generates recurring cycles of reconstruction, maintenance, and ultimately collapse. As the nation becomes inst.i.tutionally richer, more populous, and more sophisticated, it becomes difficult for Presidents to overthrow the existing political order.11 The executive's const.i.tutional powers provide the foundations for this dynamic. Skowronek's list of reconstructive Presidents is the same as this book's: Jefferson, Jackson, Lincoln, and FDR. Both lists track the Presidents usually rated as the greatest, and those elections considered pivotal in American history.12 This book examines const.i.tutional, rather than political, authority, but it is significant that the Presidents who established new governing regimes, some lasting almost 70 years (Lincoln), were also those who wielded their const.i.tutional powers in the broadest ways. Because these Presidents came at the head of parties elected to sweep away a discredited political regime, their const.i.tutional powers were critical to replacing the existing order. Executives dependent on Congress would find it far more difficult to establish the durable political orders of the Jeffersonian, Jacksonian, Republican, or New Deal periods. Congressional efforts to limit presidential power often represent the efforts of a status quo regime to prevent the rise of its successor. This book examines const.i.tutional, rather than political, authority, but it is significant that the Presidents who established new governing regimes, some lasting almost 70 years (Lincoln), were also those who wielded their const.i.tutional powers in the broadest ways. Because these Presidents came at the head of parties elected to sweep away a discredited political regime, their const.i.tutional powers were critical to replacing the existing order. Executives dependent on Congress would find it far more difficult to establish the durable political orders of the Jeffersonian, Jacksonian, Republican, or New Deal periods. Congressional efforts to limit presidential power often represent the efforts of a status quo regime to prevent the rise of its successor.

Presidents achieve greatness for more than their reconstruction of the political system. Our best Chief Executives brought the nation safely through unprecedented crises and emergencies. Washington, Lincoln, and FDR remain the three greatest because they led the country through its birth, its rebirth, and its rise to great power status. Jefferson acquired the Louisiana territory, and Jackson started the drive toward the Pacific. Our Cold War Presidents patiently pursued the strategy of containment and eventually exhausted the Soviet Union. None of our great Presidents was a stranger to controversy. They relied heavily on their unique const.i.tutional powers to take action -- the very same powers that, in other hands, could produce disaster. At the time, they were often accused of dictatorship, tyranny, and acting above the law. History has proven them right, but it has taken decades or even centuries of perspective for their vindication.

Examples of presidential greatness caution against going beyond the Const.i.tution to restrict executive power. After Watergate, Congress enacted a series of laws, such as the War Powers Resolution, intended to restrain the "imperial presidency." But within a decade, Presidents of both parties had worked around many of these statutes, without much opposition from Congress, to restore the capabilities of their office. But suppose Congress turned serious about altering the Presidency's inst.i.tutional abilities. It could attach funding cutoffs to any laws creating military units or national security functions; reenact the independent counsel law; downsize the size and scope of the White House staff; and terminate delegated authority. The powers that some Presidents have abused, however, can be the very same ones that have allowed other Presidents to become great. Reducing presidential power for fear of another Nixon or Bush (depending on one's political perspective) could also cripple another Lincoln or Roosevelt. Critics of executive power desire a risk-free Presidency, but by creating a system designed to ensure against the risks of presidential action, they would defeat the very purpose of the executive.

Efforts at reform ignore the robustness of the original const.i.tutional design. We have had poor Presidents, perhaps more than we like to admit, and we have had abusive Presidents, though perhaps fewer than commonly a.s.sumed. Our political system allows even these bad Presidents to stymie Congress and the courts, but when it comes to an unconst.i.tutional abuse of authority, our system has shown the capacity to respond. Andrew Johnson and Congress fought to a standstill on Reconstruction, and eventually the Radical Republicans prevailed through impeachment and the next election. A combination of Justice Department investigation, media reports, and impeachment forced Nixon to resign. Impeachment by a Republican Congress placed Bill Clinton on the defensive for his second term, while the 2006 midterm elections forced George W. Bush to compromise and negotiate with a Democratic Congress. Bush's ability to continue the war in Iraq in the face of vigorous opposition serves as a reminder both of the President's const.i.tutional preeminence in war and Congress's political reluctance to use its power of the purse to stop him.

THE BUSH PRESIDENCY.

GEORGE W. BUSH has sparked a resurgence in popular interest in presidential power. Many of our great and near-great leaders have been wartime Presidents, but war has also led others, such as Johnson or Nixon, to make critical errors of judgment and policy. Partisanship and poll ratings will give way to the pa.s.sage of time, just as they did to the benefit of Harry Truman and to the detriment of John F. Kennedy. What this book shows is that the claims of dictatorship or of a President acting above the law are exaggerations no different from the attacks on other vigorous Presidents. On some questions, the Bush administration acted well within the example of past Presidents; in others, it even sought greater accommodation with the other branches. Today's conflict over presidential power does not truly arise over whether the authorities in question exist, but whether now is the right time to exercise them.

War power is the most immediate and obvious example. Like Presidents before him, Bush claimed the authority to use force to defend the national security. But unlike his predecessors, he did not use it. In the wake of the September 11, 2001, terrorist attacks, the administration sought and received from Congress an Authorization to Use Military Force (AUMF). It was sweeping, perhaps the broadest grant of war power by Congress since World War II. It authorized the President "to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks."13 The AUMF recognized that "the President has the authority under the Const.i.tution to take action to deter and prevent acts of international terrorism against the United States." It was unlimited as to time or geography. Nor did Bush rely solely on his presidential power in Iraq. Again, the administration sought and received from Congress another AUMF, this time aimed at Iraq and Saddam Hussein. While not as broad as the September 11 resolution, it still granted significant power to the executive branch. Congress authorized the President to use the armed forces "as he determines to be necessary and appropriate" to achieve two objectives: "defend the national security of the United States against the continuing threat posed by Iraq" and "enforce all relevant United Nations Security Council resolutions regarding Iraq."14 Critics of the Iraq war have since claimed that the Bush administration provided misleading information to Congress. If it did so, it was nowhere as serious as President Polk's description of the events that led to the declaration of war against Mexico. But it is a mistake to think about the intelligence regarding Iraq in 2002 as the same in kind as the information about the Mexican-American War, Pearl Harbor, the Tonkin Gulf, or even Jefferson's war against the Barbary Pirates. In those conflicts, Presidents reported to Congress on events that had already occurred, and those facts either led Congress to authorize war or not. In contrast, the facts about Iraq involved prediction about the future. The decision on war did not focus on whether Iraq had aggressively acted to justify a military response, but whether the intentions and capabilities of its regime posed a sufficient threat to justify a preemptive attack. Such judgments will involve speculations, guesses, and estimates of future costs and benefits that may turn out to be wrong, but we should not confuse mistakes for a conspiracy.

If Congress were serious about claims that the executive branch deliberately misled it, it could have used its powers over funding, oversight, and legislation to influence the intelligence agencies. Select committees in the House and Senate had received cla.s.sified briefings from the CIA on all covert operations and intelligence programs. If Congress believed that the executive branch deliberately manipulated information about Iraq, it could have restructured or cut funding for the national security agencies and programs. Or, ultimately, it could have impeached the President.

Putting the justification for war to one side, much of today's controversy over presidential power has settled on the conduct, rather than the initiation, of war. Critics of the Bush administration attacked the "surge" strategy of sending more troops to Iraq to secure Baghdad and its surrounding provinces. They argued that the executive branch cannot detain prisoners in the war on terrorism at the U.S. naval base at Guantanamo Bay, Cuba. They challenged the use of coercive interrogation measures on al Qaeda leaders and the establishment of military commissions for the trial of terrorists. They claimed that the National Security Agency's surveillance of the communications of suspected terrorists without a warrant, inside the United States, violated federal law and the Fourth Amendment.

Critics went to Congress to cut off funds for the Iraq war, but failed. Proposals to restrict the warrantless surveillance of suspected terrorists went nowhere. The opposition found more success in its efforts to seek legislation regulating military interrogation and trials. Critics have won some successes in the Supreme Court, which extended its jurisdiction in 2004 to hear cases arising out of Guantanamo Bay, blocked portions of the military commission rules in 2006, and expanded the right of the judiciary to review military detention decisions in 2008.

President Bush initially undertook many of these policies under his powers as Chief Executive and Commander-in-Chief. To be sure, the administration made broad claims about its powers under the President's const.i.tutional authorities, but this book shows that it could look to past Presidents for support. Presidents have used force abroad without any legislative authorization at all, and several made the most important strategic decisions without any input from Congress. Lincoln and Roosevelt, for example, resisted or overrode efforts by Congress to interfere with their judgments about the steps necessary to protect the national security. The Emanc.i.p.ation Proclamation stands as a striking example of a presidential decision on the conduct of war -- to free the slaves and undermine the Confederacy's vital labor source -- which was inconsistent with Congress's preferences. Presidents have long exercised the widest discretion over the conduct of war and have fought jealously to defend their prerogatives. Congress, for the most part, has respected presidential discretion, and the times when it has not, as in the War of 1812 and the beginnings of World War II, it has done no better and sometimes much worse than the President. Congress simply does not have the ability to make effective, long-term national security decisions because of the difficulty in organizing 535 legislators and the political incentives that drive them toward short-term, risk-averse thinking.

Despite low approval ratings, President Bush succeeded in defending many of his war priorities. In Iraq, the administration won continued funding from Congress for the surge of troops, without any strings attached, such as a withdrawal date or a mandated reduction in operations. In the Detainee Treatment Act of 2005 and the Military Commission Act of 2006, Bush won support for the use of military commissions and the exclusion of the Supreme Court from reviewing the detention of terrorists. Congress did set rules for the interrogation of prisoners held by the U.S. armed forces, but it did not extend those guidelines to the CIA. Similarly, President Bush went to Congress to seek support for his warrantless surveillance program. In the Protect America Act, Congress responded by giving its temporary blessing and providing immunity to telecommunications companies that had helped carry out the surveillance after the 9/11 attacks.15 Other exercises of executive power have simply been blown out of proportion. A salient example is the issue of presidential signing statements. In 2006, a media report claimed that President Bush had used signing statements to claim "the authority to disregard more than 750 laws enacted since he took office." The American Bar a.s.sociation a.s.sembled a task force that concluded that such statements were "contrary to the rule of law and our const.i.tutional system of separation of powers." The Senate Judiciary Committee followed with hearings criticizing them as a "grave threat to our const.i.tutional system of checks and balances." These reports would lead a stranger to this land to think that by issuing a statement when signing a bill, even one that provided an interpretation of the law or found parts of it unconst.i.tutional, President Bush had brought down republican government.16 Careful examination of the issue shows that nothing of the sort has happened. Presidents have issued statements to explain their reasons for approving or disapproving a bill, almost from the beginning of the Republic. Jackson's lengthy message explaining his veto of the Bank of the United States was little different in purpose from a signing statement. To be sure, Presidents did not use statements frequently until the twentieth century. Beginning with Truman, Presidents issued statements that they would interpret laws to avoid causing const.i.tutional problems, refuse to obey provisions that they believed violated the Const.i.tution, or explain their preferred interpretation of ambiguous statutory language. By the Clinton administration, an average of between 35 and 60 were issued a year. Many of the statements discuss policy or feature political rhetoric rather than interpret legislation or comment on its const.i.tutionality. It does not appear that courts give these declarations much, if any, weight. A more careful study of the Bush administration's practices finds that it issued signing statements challenging statutory provisions at a rate within the historical norms for postwar Presidents, though it questioned the const.i.tutionality of more provisions per bill.17 Signing statements themselves can present reasonable defenses against legislative encroachments. In many, for example, President Bush objected to laws that required the executive branch to propose legislation to Congress -- most would agree that Article II gives the President the discretion whether to do so. In others, Bush objected to congressional efforts to vest the power to appoint executive branch officers in people or ent.i.ties outside the Appointments Clause. Sometimes the administration challenged provisions ordering it to take a certain diplomatic position, vote a certain way in an international organization, or limit the use of the armed forces abroad. While Bush received criticism for signing the Military Commission Act with the proviso that he would interpret it consistent with his Commander-in-Chief authority, President Clinton relied on the same ground in refusing to obey a congressional prohibition on placing American troops under foreign commanders. A recent study finds that President Clinton issued signing statements virtually identical in substance, though fewer in number, on all of these issues.18 President Obama has issued signing statements in his first few months in office that continue the Bush practice in form and function, especially in the area of foreign affairs. President Obama has issued signing statements in his first few months in office that continue the Bush practice in form and function, especially in the area of foreign affairs.

Bush's use of signing statements has been exaggerated into a caricature. A desire to spin a story of an out-of-control President has overlooked their modest purposes. Signing statements are not really aimed at the courts, which do not take them into account, or even to Congress, which is not bound by them. Instead, they communicate presidential policy and interpretation to subordinate officers and agencies within the executive branch. Presidents can just as easily reach the same result by issuing a memorandum to cabinet secretaries and agency heads setting out the same instructions, minus the public transparency of a public statement. The President need not even declare that he believes a law violates the Const.i.tution, the very move that stoked the controversy in the first place. As we have seen, the Const.i.tution itself places the responsibility on the President to execute the laws -- and the Const.i.tution is the supreme law. A presidential declaration that he will not enforce acts of Congress that violate the Const.i.tution merely states a truism.

Some argue that the President has an obligation to veto an unconst.i.tutional law, rather than sign it and decline to enforce it. To be true to his oath of office, the argument goes, the President cannot approve an unconst.i.tutional act.19 This argument ignores laws that were enacted before a President a.s.sumed office (as with Jefferson and the Alien and Sedition Acts) or laws pa.s.sed over his veto (as with Nixon and the War Powers Resolution). But even if such a principle applied to bills signed during a President's own administration, it fails to take note of changes in the legislative process. Gone are the days when Congress enacted laws of brevity and conciseness. Congress today enacts ma.s.sive omnibus legislation that combines provisions on multiple subjects along with spending needed to keep the government open. A President who signs legislation to keep normal functions going cannot thereby have his right to interpret the Const.i.tution taken away. Members of Congress have a parallel obligation not to vote for bills that contain unconst.i.tutional provisions, but they do so anyway for the same reason as the President's -- they cannot vote against omnibus legislation containing vital appropriations. Today, it is not unusual to hear Congressmen declare that if part of a bill violates the Const.i.tution, the Supreme Court should attend to the problems. This argument ignores laws that were enacted before a President a.s.sumed office (as with Jefferson and the Alien and Sedition Acts) or laws pa.s.sed over his veto (as with Nixon and the War Powers Resolution). But even if such a principle applied to bills signed during a President's own administration, it fails to take note of changes in the legislative process. Gone are the days when Congress enacted laws of brevity and conciseness. Congress today enacts ma.s.sive omnibus legislation that combines provisions on multiple subjects along with spending needed to keep the government open. A President who signs legislation to keep normal functions going cannot thereby have his right to interpret the Const.i.tution taken away. Members of Congress have a parallel obligation not to vote for bills that contain unconst.i.tutional provisions, but they do so anyway for the same reason as the President's -- they cannot vote against omnibus legislation containing vital appropriations. Today, it is not unusual to hear Congressmen declare that if part of a bill violates the Const.i.tution, the Supreme Court should attend to the problems.

President Bush reached for a broad vision of executive power. Whether his claims ultimately have merit depends on whether they were used at the right moment. Our Framers designed the executive branch to be a government always in being that could respond quickly and with vigor to unforeseen emergencies and crises. Presidential power expands to meet them, and withdraws when they are over. During peacetime conditions, when there are few threats to the national security, the const.i.tutional role of the President remains limited, and that of Congress is ascendant. During wartime, those roles are reversed, but that does not mean that the sudden expansion of presidential power in response to emergency ever occurs smoothly. Beginning with President Washington's declaration of neutrality in the European wars, the mobilization of the executive branch to meet crises has fallen under fire as dictatorial and tyrannical.

Two developments have contributed to the modern controversy over executive power. The first is the great expansion of economic and social regulation during the New Deal and postwar period. Critics of presidential power usually raise the specter of a ma.s.sive executive branch that has broken free of its checks and balances, like a King Kong bursting his chains, but they are often silent when it comes to the changes that produced the ma.s.sive bureaucracy of the New Deal state. If the executive branch has become a permanent establishment dwarfing Congress and the courts, it is in part because of Congress's delegation of power to the agencies to manage the economy and society. Those who worry about executive power often have no qualms about national education standards, pollution controls, or housing programs. If critics were to enforce the same standards about executive power in its domestic dimension that they would in foreign affairs, they would have to accept a return to a domestic regime of limited government and largely unregulated markets.

On the domestic front, the Bush administration's exercise of presidential power followed the path marked by its predecessors. Bush claimed privileges to shield discussions internal to the executive branch from Congress and private litigants, but he was not the first, nor even the most aggressive to do so. Eisenhower claimed a greater scope for secrecy, reaching down to anyone in the executive branch, while Clinton argued that it extended to activities that fell outside his official duties. Bush moved to make his mark on the judiciary by appointing Supreme Court Justices and lower court judges who shared his const.i.tutional philosophy, but again, that made him no different from Presidents since at least Nixon. Bush used his position as Chief Executive and party leader to coordinate with his congressional majorities, but he was only following in the mold of Presidents since Jefferson. Like his predecessors, Bush sought to deepen his control so as to bring coherence and rationality to the administrative state. His exercise of power may have been different in amount, but not in kind.

The second, and sharper, area of controversy involved foreign affairs. President Bush's actions relied on broad claims of presidential power, but again they fell within the precedents set by earlier Presidents. President Bush, for example, terminated the Anti-Ballistic Missile Treaty with the Soviet Union without the approval of the House or the Senate, but Presidents have terminated treaties since at least President Lincoln. When Senator Barry Goldwater sued to block President Carter's decision to end the Mutual Defense Treaty with Taiwan, the federal appeals court in Washington, D.C., vindicated the President, and the Supreme Court refused to reach the merits. (Four Justices agreed that the case posed a political question that lay outside the judicial power.) President Bush declined to apply the Geneva Conventions' protections for prisoners of war to members of al Qaeda and the Taliban captured fighting in Afghanistan. He concluded that al Qaeda was not a signatory to the Conventions and that the Taliban did not meet the standards for lawful combatants, such as fighting in organized units with visible uniforms and arms in the open, while following the laws of war. Presidents have interpreted treaties since President Washington's proclamation of neutrality. President Clinton, for example, claimed that the ABM Treaty remained in existence even after the Soviet Union had collapsed into 15 independent states.20 Most of the opposition to the Bush administration's exercise of its powers focuses even more tightly not just on foreign affairs, but on the war on terrorism. The Framers vested the executive branch with a unitary design and broad authority precisely so it could respond to the demands of war. Structurally, a branch headed by a single person can process information more easily, a.n.a.lyze the situation and make decisions faster, and implement policies decisively and vigorously. In contrast, Congress's large numbers create severe transaction costs that prevent it from organizing and acting quickly, and the courts act slowly and address only issues that arise as a case or controversy under federal law. "Decision, activity, secrecy, dispatch will generally characterize the proceedings of one man, in a much more eminent degree, than the proceedings of any greater number," Hamilton reminds us in Federalist 70 Federalist 70, "and in proportion as the number is increased, those qualities will be diminished."21 The Framers vested the President with the executive power and the role of Commander-in-Chief so he could marshal the nation's military with speed and decision to defeat its external foes. The Framers vested the President with the executive power and the role of Commander-in-Chief so he could marshal the nation's military with speed and decision to defeat its external foes.

Every President since World War II has consistently argued that the Const.i.tution gives him the right to use force abroad to protect the nation's security and interests. Presidents have consistently refused to obey the War Powers Resolution, and Congress has often recognized the President's right to use force, not just in the 2001 Authorization to Use Military Force, but in its acquiescence to the numerous presidentially led interventions abroad. Even the Youngstown Youngstown case, much beloved by supporters of congressional authority, does not take away the President's powers abroad. case, much beloved by supporters of congressional authority, does not take away the President's powers abroad. Youngstown Youngstown held that the regulation of the steel mills in wartime remained within Congress's power to legislate on domestic affairs. It did not address the scope of the President's authority over the armed forces in the theater of war, nor did it address the Commander-in-Chief's power to set military strategy or tactics, direct the military, or gather intelligence. held that the regulation of the steel mills in wartime remained within Congress's power to legislate on domestic affairs. It did not address the scope of the President's authority over the armed forces in the theater of war, nor did it address the Commander-in-Chief's power to set military strategy or tactics, direct the military, or gather intelligence. Youngstown Youngstown even acknowledges that if Congress attempts to limit presidential action, the executive could prevail by relying on "his own const.i.tutional powers minus any const.i.tutional powers of Congress over the matter." even acknowledges that if Congress attempts to limit presidential action, the executive could prevail by relying on "his own const.i.tutional powers minus any const.i.tutional powers of Congress over the matter."22 The Bush administration's claims of executive authority in the war on terrorism fell into the tactical and strategic decisions appropriate to the Commander-in-Chief. Commanders have long set the standards for the capture and treatment of enemy prisoners. The executive branch has played the leading role in the development and enforcement of the laws of armed conflict. The Lincoln administration issued the first code of the laws of war. The Wilson administration found that unrestricted submarine warfare was a casus belli casus belli. FDR approved the strategic bombing of Germany and j.a.pan, even when hundreds of thousands of civilians were killed -- a position put on stark display by President Truman's decision to drop the atomic bomb. President Reagan refused to adopt an international agreement extending the Geneva Conventions to irregular fighters because it would have given terrorists the same status as regular troops. While Congress has the power over funding, creation of the military, and the authority to pa.s.s laws for the "Government and Regulation of the land and naval Forces," it has never sought to prevent the President from making the critical decisions about the best means to prevail on the battlefield.

Even the Bush administration's domestic pursuit of al Qaeda terrorists, while controversial, followed the example of past Presidents confronted with grave security challenges. The military has detained hundreds of al Qaeda terrorists at Guantanamo Bay without access to civilian courts, and has established military commissions to try dozens of them for war crimes. Bush designated several U.S. citizens and permanent resident aliens as enemy combatants and ordered their detention without criminal trial as well. While not punitive, as is imprisonment in the civilian justice system, the detentions seek to prevent a member of the enemy from returning to the fight. President Bush ordered the warrantless interception of electronic communications involving suspected terrorists coming into or out of the United States. Like detention, the warrantless Terrorist Surveillance Program does not seek information to use in convicting terrorists in court. It only intercepts communications that would allow the intelligence agencies or armed forces to take action to prevent an attack on the United States.

Earlier Presidents used similar means on the home front. President Lincoln detained thousands of citizens behind the Union lines, used military commissions to try suspected Confederate agents, and suspended habeas corpus. When the federal courts today have sought to extend habeas to broader cla.s.ses, such as non-U.S. citizens held outside the United States at Guantanamo Bay, Congress and the President have joined together to overrule them, sparking yet another round of struggle with the courts.23 FDR used military commissions to try U.S. citizens who had joined the Axis powers, interned 120,000 j.a.panese-American citizens, and inst.i.tuted a sweeping surveillance program that intercepted all electronic communications within the nation's borders. This is not to argue that Bush's counterterrorism policies stand out because they reduced civil liberties less than these historical examples. Instead, the record of practice shows that the United States has always had to balance civil liberties and security interests and that in wartime, liberties will be narrowed to give the government broader freedom to win a war. Unless the government is to be prevented from making any adjustment in the trade-off between security and liberty, the executive will be the branch that often must strike that balance in wartime. FDR used military commissions to try U.S. citizens who had joined the Axis powers, interned 120,000 j.a.panese-American citizens, and inst.i.tuted a sweeping surveillance program that intercepted all electronic communications within the nation's borders. This is not to argue that Bush's counterterrorism policies stand out because they reduced civil liberties less than these historical examples. Instead, the record of practice shows that the United States has always had to balance civil liberties and security interests and that in wartime, liberties will be narrowed to give the government broader freedom to win a war. Unless the government is to be prevented from making any adjustment in the trade-off between security and liberty, the executive will be the branch that often must strike that balance in wartime.

The war on terrorism provides a cautionary tale about current proposals to rein in executive power. Despite the executive's const.i.tutional powers, Congress always has the ability to counter the President. Trying to force the President to a.s.sume less initiative may make the office more comfortable for the risk-averse, but it may also prevent the executive branch from rising to the great challenges confronting the nation. After Watergate, Congress embarked on a similar mission by pa.s.sing a horde of statutes intended to hamstring future Presidents.

Some of the new statutes had little effect, some had a large one. One of those, the Foreign Intelligence Surveillance Act, required that Presidents obtain a warrant from the federal FISA court before they could pursue domestic wiretapping for national security purposes. The courts and the Justice Department read the law to prohibit the sharing of the fruits of such intelligence with domestic law enforcement officials. As American security agencies attempted to track down al Qaeda agents who had entered the country in the summer of 2001, FISA prevented the CIA from informing the FBI about the ident.i.ties and photographs of some of the 9/11 hijackers already in the country. FISA was pa.s.sed with the best of intentions, to prevent another Richard Nixon from ever using the intelligence agencies to hara.s.s his domestic opponents, but it also blocked the executive branch from taking the swift action necessary to prevent a devastating attack on the American homeland.24 No one wants another Nixon to abuse his powers to attack his political enemies, but the restraints necessary to prevent another Nixon or Andrew Johnson may sap the executive of those unique qualities that allow it to act decisively when the nation's security is at stake. The flexibility necessary for an energetic executive can serve bad as well as good ends. For the bad, our const.i.tutional system seems up to the job. It has adequately handled the abusive Presidents with political resistance or by forcing them from office. While the poor Presidents have cost the nation dearly, Washington, Lincoln, and FDR brought the nation much more benefit, including national survival. If allowing Presidents to exercise their const.i.tutional powers freely risks executive abuse, it also brings with it the promise of flexibility and energy to meet national emergencies and crises.

RETURNING TO FIRST THINGS.

BUSH'S REPUTATION WILL depend on whether future historians judge his exercise of presidential power to have been justified by the circ.u.mstances. If the September 11, 2001, attacks marked the emergence of a serious foreign threat to the nation's security, the invocation of broad presidential powers will have been appropriate. Presidents like Lincoln and FDR may have gone too far at times, but we forgive them their trespa.s.ses because they led us through the Civil War and World War II. If it turns out that the United States had overreacted to what was essentially an isolated event, the exercise of presidential power will prove to have been unnecessary and counterproductive. The difficulty in reaching a judgment now is that we are still living through the period of threat, and we cannot judge ex post whether the long-term reorientation of national security powers was necessary to meet it. This is not to argue that Bush is destined to rank among the great Presidents or even those considered above-average. It means that only when we have the benefit of distance will we know whether Bush's aggressive use of executive authority was too much, too little, or just right.

Understanding the contingency of our current circ.u.mstances brings us back to where we began, the purpose of the executive. As originally conceived, the need for the executive arose to respond to unforeseen dangers, unpredictable circ.u.mstances, and emergencies. It was given the virtues of speed, secrecy, vigor, and decisiveness to most effectively marshal society's resources in a time of crisis. The executive could correct for the instability, fractiousness, and inability to organize and decide (caused by what we today think of as transaction costs of a republican legislature) under time pressure. If the circ.u.mstances demand, the executive can even go beyond the standing laws in order to meet a greater threat to the nation's security.

It remains an open question whether the Const.i.tution incorporated this prerogative. Hamilton believed that Article II's vesting of the executive power in the President necessarily included the ability to meet any challenge. To him, this power ought to "exist without limitation because" the "circ.u.mstances that endanger the safety of nations are infinite." There was no prerogative in the Lockean mold, only a President with open-ended powers in time of emergency. This broad conception of the executive underpinned the broader Hamiltonian program. A President of broad powers would guide the national government by developing proposals, managing legislation, and vigorously enforcing the law and setting foreign policy. In contrast, Jefferson believed that the President's ability to access the prerogative existed independent of the Const.i.tution. To him, the natural right of self-preservation allowed the President to act beyond the Const.i.tution itself when defending the nation. Whereas Locke believed that the executive would have to appeal to the heavens in the event of an exercise of the prerogative, Jefferson believed that an appeal to the nation was in order.

The prerogative allowed Jefferson to keep his devotion to a strict interpretation of the Const.i.tution. If the prerogative could serve as a safety valve when emergency placed the government under stress, the Const.i.tution would need no stretching. The government's powers would remain limited, rather than permanently extended, and individual liberty and hopefully state sovereignty would be preserved. The process for confirming the executive's use of the prerogative, an appeal to the people, advanced Jefferson's agenda to make the President the democratic representative of the nation as a whole. Jefferson did not believe that the approval of Congress or the courts alone was necessary, except insofar as they represented the will of the people.

History suggests that Hamilton had the better argument. The prerogative faces serious, perhaps fatal problems, chief of which is that it requires the executive to violate the Const.i.tution. If the people bless executive lawbreaking, then they undermine the very purpose of the Const.i.tution to bind future majorities. Although faced with the most serious threats to the nation's security, Lincoln and FDR did not claim a right to act outside the Const.i.tution. While Lincoln suggested on several occasions that it might be necessary to violate the Const.i.tution to save the nation, he never invoked the prerogative. In fact, he carefully argued that his every action, from using force against secession to the Emanc.i.p.ation Proclamation, was justified by his const.i.tutional authorities. Roosevelt, too, never claimed the prerogative, and justified his actions by his authority as Commander-in-Chief. By the Cold War, the debate seemed to be over -- the Const.i.tution accommodated the need to respond to extraordinary events through the President's executive power.

At first glance, it might appear that this understanding of the Const.i.tution could only work to the benefit of the President. It allows him to claim a reservoir of power to meet any serious threat to the national security. But subordinating the prerogative to the law may have come with costs as well -- it has raised public expectations of the President to the point where no mere mortal can satisfy them. If the President has the const.i.tutional authority to respond to any emergency, then the failure of the government to meet the latest national problem must be his fault.

A second effect may be the unwillingness of Presidents since FDR to challenge the Supreme Court. Presidents no longer claim an independent right to interpret the Const.i.tution differently from the judiciary, giving up the inheritance of Jefferson, Jackson, Lincoln, and Roosevelt. There are understandable political reasons for this, but perhaps a deeper const.i.tutional explanation lies in presidential adoption of the Hamiltonian theory of the executive. If the President accesses extraordinary power from the Const.i.tution, he may seek judicial approval in order to address concerns that he is interpreting the Const.i.tution solely for his own benefit. It is not clear whether this bargain is to the long-term benefit of the inst.i.tution; abdicating the right to interpret the Const.i.tution, in light of the President's obligation to enforce the laws, ultimately places the definition of his duties and powers solely in the hands of another branch. Presidents may have only won themselves the freedom to act in the short term, but they have left the long-term success in the hands of others.

The fundamental question of the prerogative lends presidential power a tragic quality. Due to the Const.i.tution's design, the political system has great difficulty responding to unforeseen circ.u.mstances, fast-moving events, or decisions that require technical expertise or run high political risks. It will fall to the President to act at these times, which most often arise where the nation's foreign relations and national security are at stake. In exercising their const.i.tutional powers, Presidents by definition act against the web of congressional statutes, court decisions, agency regulations, and interest groups that make up the political status quo. Invocation of executive authority is guaranteed to trigger a sharp response by the supporters of the governing regime.

In their own time, our greatest Presidents have been the subject of terrible attacks, ranging from accusations of personal immorality to the formation of opposition political parties. Nevertheless, our greatest Presidents have had to act because they have judged their actions necessary to benefit the nation or protect it from harm. Presidential power takes on a tragic dimension when our Chief Executives exercise their const.i.tutional powers knowing that it could lead to their political ruin or damage their historical reputations. But as we have seen, presidential power moves in cycles, change is no doubt certain, and it is change that can bring out greatness in our Presidents.

AFTERWORD.

"YOU NEVER WANT a serious crisis to go to waste," Rahm Emanuel, the new White House Chief of Staff, said in the early months of the Obama administration.1 Barack Obama's election as America's forty-third President was historic for many reasons. Obama entered office amid what may be the worst economic recession since the Great Depression. Gross domestic product estimates nose-dived a stunning 6.3 percent in the fourth quarter of 2008 and fell another 5.7 percent in the first three months of 2009. Barack Obama's election as America's forty-third President was historic for many reasons. Obama entered office amid what may be the worst economic recession since the Great Depression. Gross domestic product estimates nose-dived a stunning 6.3 percent in the fourth quarter of 2008 and fell another 5.7 percent in the first three months of 2009.2 The stock market fell about one-third in 2008, destroying trillions in private wealth. The stock market fell about one-third in 2008, destroying trillions in private wealth.3 The unemployment rate leapt from 4.6 percent to 7.1 percent in 2008 -- 2.7 million Americans lost their jobs, General Motors and Chrysler went bankrupt, while industrials like Alcoa and DuPont announced ma.s.s layoffs. Unemployment continued to rise after the inauguration, continuing upward to more than 9 percent by the middle of 2009. The unemployment rate leapt from 4.6 percent to 7.1 percent in 2008 -- 2.7 million Americans lost their jobs, General Motors and Chrysler went bankrupt, while industrials like Alcoa and DuPont announced ma.s.s layoffs. Unemployment continued to rise after the inauguration, continuing upward to more than 9 percent by the middle of 2009.4Only the recessions of 1974-75 and 1982-83 threw a higher fraction of postwar Americans out of work.5 Obama's a.s.sumption of office in the midst of trying economic times recalled the transitions between Hoover and FDR and between Carter and Reagan. Obama's a.s.sumption of office in the midst of trying economic times recalled the transitions between Hoover and FDR and between Carter and Reagan.

Foreign dangers also greeted the new President. Obama took the oath of office while the nation fought wars in Iraq and Afghanistan. Al Qaeda, which, along with its Taliban allies, continues to destabilize nuclear-armed Pakistan, remains a threat.6 North Korea, the most brutal totalitarian dictatorship on the planet, successfully tested a nuclear weapon and continues its quest for a long-range ballistic missile capable of reaching the United States. North Korea, the most brutal totalitarian dictatorship on the planet, successfully tested a nuclear weapon and continues its quest for a long-range ballistic missile capable of reaching the United States.7 And Iran, another consistent foe of the United States, continued its own efforts to acquire nuclear weapons and ballistic missile technology in defiance of international sanctions. And Iran, another consistent foe of the United States, continued its own efforts to acquire nuclear weapons and ballistic missile technology in defiance of international sanctions.8 The United States transferred power between the two major political parties during the Cold War, but it did not elect new regimes during any previous "hot" war except for the elections of Eisenhower during the Korean War and Nixon during the Vietnam conflict. The United States transferred power between the two major political parties during the Cold War, but it did not elect new regimes during any previous "hot" war except for the elections of Eisenhower during the Korean War and Nixon during the Vietnam conflict.

But as Emanuel's quip recognizes, crisis presents opportunity. Obama is the first African American elected to the nation's highest office, giving many hope of a post-racial future. His election might also portend, in the view of some, one of those rare realignments in American politics that have accompanied the elections of several of the great Presidents studied in this book -- Washington, Jefferson, Jackson, Lincoln, FDR, and Reagan. Not only did Obama win the 2008 election decisively, by 52-46 percent of the popular vote and 365-173 in the Electoral College, but Democrats picked up 6 seats in the Senate and 20 in the House of Representatives. After the Minnesota Supreme Court declared Al Franken the winner of a Minnesota Senate seat in June 2009, Democrats gained a filibuster-proof majority in the Senate, in addition to their already secure 254-173 majority in the House.9 Obama, however, has a difficult course to chart. While he and his party won large majorities, he must navigate between overreaching and timidity. Americans of all stripes celebrated that the United States had elected the first African American to the Presidency. But Obama should resist the temptation to view his victory as a fundamental realignment of the political system. Obama is only the second Democratic presidential candidate to win more than 51 percent of the vote since FDR in 1944, and the first since Lyndon Johnson's landslide (Carter won in 1976 with only 50.1 percent). One of the Electoral College's effects is to magnify the political legitimacy of the winner beyond that bestowed by the popular vote alone. For example, even though he never won a popular majority, Bill Clinton won the 1992 election by 370 electoral votes to 168 for President George