The presidential legacy of George W. Bush is perhaps best expressed in four words: He kept America safe.
Many legal scholars question President Bush's claim to unilateral power as commander in chief in the war on terror. And experts will long debate his aggressive approach to the fight against Al Qaeda – authorizing warrantless wiretaps within the US, secret kidnappings of terror suspects, coercive interrogation tactics, and military commissions with stripped-down legal protections.
But even Mr. Bush's harshest critics must concede that on his watch the country remained free of further terrorist atrocities following the 9/11 attacks.
The deeper question is at what price?
At the heart of the debate over Bush's legacy is a fundamental difference in outlook over what it means to remain faithful to the constitutional protections laid down by America's founding generation.
Critics say the Bush administration's expansive vision of executive power eclipsed the Constitution's mandated system of checks and balances. Some see the Bush years as lurching toward an imperial presidency, posing a direct threat to the essence of American liberty.
"The breadth of the theory that they were articulating is as broad as any theory of presidential power offered by any administration in history," says Gene Healy, a vice president at the Cato Institute in Washington and author of "The Cult of the Presidency: America's Dangerous Devotion to Executive Power."
Others disagree. "President Bush clearly had constitutional authority to make the military and counterterrorism decisions that he did," says Michael Paulsen, a constitutional scholar at the University of St. Thomas in Minneapolis. "I can think of none of President Bush's actions that fall outside those categories of relatively clear commander-in-chief clause power."
Bush, Vice President Dick Cheney, and administration advisers insist that their actions have been fully consistent with the Constitution.
Historical precedent for Bush actions
Every president since George Washington has sworn an oath to "preserve, protect and defend the Constitution of the United States." But presidents have interpreted that sacred pledge in different ways.
Some read it narrowly, that the president must always act within the strict letter and spirit of the law and Constitution. Others viewed it more broadly, embracing a duty to protect the nation itself, even when specific actions might temporarily violate the Constitution or laws.
Abraham Lincoln interpreted his presidential oath as a pledge to preserve the Union and the government itself. In 1861 amid a mounting crisis over the possible secession of Maryland, he suspended the writ of habeas corpus, a protection reserved under the Constitution to Congress.
Had Lincoln called Congress into special session in Washington, just as Maryland pulled out of the Union, the entire government would have been located within the Confederacy and in grave danger.
Instead, Lincoln acted quickly and alone. Then, within months, once the crisis in Maryland subsided, he presented the issue to Congress and obtained its approval.
Bush administration members invoked the example of Lincoln as justification for their own assertions of executive authority in the war on terror. But some analysts say the Bush administration wrongly sought to act alone in controversial areas, rather than obtaining the guidance and support of Congress.
"Given the kind of conflict we're faced with today, we find ourselves in a situation where I believe you need strong executive leadership," Mr. Cheney said in a FOX News interview in December. "There are bound to be debates and arguments ... about what kind of authority is appropriate in any specific circumstance. But I think that what we've done has been totally consistent with what the Constitution provides for."
Cheney noted that the president has 24-hour access to a briefcase containing all the codes necessary to launch a nuclear counterattack. "He could launch a kind of a devastating attack the world has never seen," the vice president said. "He doesn't have to check with anybody. He doesn't have to call Congress. He doesn't have to check with the courts. He has that authority because of the nature of the world we live in."
Many scholars take issue with Cheney's view. They say he and others in the Bush administration have used the war on terror as an opportunity to try to establish more robust powers within the executive.
"The basic strategy was to assert that the president could do various things like [authorizing domestic] wiretaps, detaining enemy combatants, and setting up military commissions solely on his own, he didn't need congressional authorization," says Steven Calabresi, a constitutional scholar at the Northwestern University School of Law in Chicago and author of "The Unitary Executive: Presidential Power from Washington to Bush."
"The hope was that by President Bush doing those things on his own it would vindicate presidential power in those areas," Professor Calabresi says. "I think that strategy was a mistake both legally and politically."
Cheney's strong hand seen
"Cheney is an executivist in the sense that he really thinks the president needs all that power and control to defend the country," says James Pfiffner, a political scientist at George Mason University in Fairfax, Va, and author of "Power Play: The Bush Presidency and the Constitution."
"There is a difference between power and authority," Professor Pfiffner says. "The president has the power to push the [nuclear] buttons, but he doesn't have the constitutional authority to do that. That rests with Congress."
Congress can delegate the power to the president to be prepared to respond immediately to a sudden attack. But the president does not possess the constitutional authority to launch and fight a war without congressional approval.
"Immediately repelling attacks is constitutionally entirely appropriate," Pfiffner says. "But Cheney wants to extend that and say that things are different now that we are under big threats, so you have to give all this power to the executive."
The effort did not fail, experts say. But it did not succeed either.
"I think probably the hopes of the president and vice president for creating a much stronger executive branch have been largely frustrated," says Bradford Berenson, a former associate White House counsel under Bush.
"In the Bush years the hope for revivifying presidential power ended up foundering on some of the war on terror-related policies that Congress and the public ultimately perceived as too pro-executive or too unilateral," Mr. Berenson says.
Some analysts say it is only a matter of time before the Bush and Cheney position is vindicated.
"Over the long term the view will come to be that President Bush was largely successful in restoring the full constitutional powers of the president as commander in chief during time of war and crisis," says Professor Paulsen.
He says President Bush's terror policies were supported by Congress, including via legislation specially written to overturn Supreme Court decisions and amend domestic surveillance laws.
"Ironically, President Bush's use of war powers was much more fully supported by Congress than were President Clinton's," Paulsen says. President Clinton ordered offensive US military operations in Kosovo, he says, without any authorization from Congress.
Paulsen acknowledges that the administration lost several important cases in the US Supreme Court. But he says over time those decisions will be viewed as "far more questionable on legal grounds than President Bush's decisions."
Historians like activist presidents
Cato's Healy agrees that history may be kind to Bush, but for a different reason. "Historians tend to overvalue presidents who provide a lot of drama and explosions," he says. "This is more a reflection of the perverse fascination with activist presidents who provide a lot of drama than it is on President Bush's actual performance, which I think has been quite awful."
Bush isn't the only president who sought to greatly expand his executive powers. Lincoln did it while trying to hold the union together and win a civil war. Franklin Roosevelt did it when he ordered the open-ended internment of American citizens of Japanese heritage during World War II. Harry Truman did it when he tried to use his commander in chief powers to take over the steel mills in 1952.
The Supreme Court precedent from the Truman debacle established the principle that presidents are at the zenith of their power when they act with Congress. It also established that presidential power is at its lowest ebb when the president acts alone in defiance of Congress.
Although the Supreme Court dealt the Bush administration setbacks in cases involving detainees and military commissions at the Guantánamo Bay prison camp, the high court has never directly ruled on the constitutionality of the administration's claims of unilateral commander in chief power. The terror cases were all decided on lesser legal arguments.
That means Bush's arguments are still available for future presidents. But the Bush experience could cut either way, analysts say. "If you think about lawyers in a future administration arguing about whether a similar claim [of executive power] is right or wrong, those who argue that it is wrong or at least unwise will be strengthened in their arguments [by Bush's record,]" Berenson says.
"I wouldn't say the Bush administration has done more harm than good to executive authority, but they have done less good then they hoped to," he says.
Will other presidents expand power?
Pfiffner sees a looming threat from the Bush example. "In general, executive power tends to ratchet up; it is less like a pendulum and more like a ratchet," he says. "Bush created precedents of constitutional claims to executive power that other presidents have not. So in that sense he has made the institution more powerful and future presidents can point to that and say Bush did it."
Ironically, future terror attacks may play the most decisive role in shaping how history views the Bush presidency.
"If we are attacked again and there is major loss of life, I think Bush's stock will soar and people will conclude that a lot of what he was doing was absolutely essential," says Professor Calabresi.
But he adds: "If there are no additional attacks and the whole terrorism threat seems to have fizzled out then I think people will be skeptical of what Bush did in fighting the war on terror and think it was unnecessary."
Several analysts echo an assessment made by former Bush legal adviser Jack Goldsmith in his book "The Terror Presidency." Mr. Goldsmith, now a law professor at Harvard, has said the administration could have gotten most of what it wanted had it reached out to Congress instead of trying to act unilaterally.
In his book, he writes: "When an administration makes little attempt to work with the other institutions of our government and makes it a public priority to emphasize that its aim is to expand its power, Congress, the courts, and the public listen carefully, and worry."
Professor Goldsmith says Bush failed to follow the lessons of Lincoln and Roosevelt, that greatness resides not in the ability to command but in the responsibility to persuade and inspire.
"[Bush] has been almost entirely inattentive to the soft factors of legitimation – consultation, deliberation, the appearance of deference, and credible expressions of public concern for constitutional and international values – in his dealings with Congress, the courts, and allies," Goldsmith writes.
In these failings are important lessons.
"I think the enduring legacy of the Bush administration in the separation of powers realm will be a renewed appreciation of the fact that whatever the limits of unilateral executive authority may be, the executive is strongest when it is acting in partnership with the legislative branch," former White House associate counsel Berenson says. "That is the deepest, ultimate lesson from the administration."
•Thursday: Bush's foreign-policy record.