The swiftly decided military conflict boosted Bush's standing in polls and strengthened his reelection prospects. But the unsettled postwar situation looms as a potential long-term political threat for the president, some analysts believe.
So far, rising public concern about the steady procession of U.S. casualties from guerrilla attacks in Iraq has not eroded support for the effort to rebuild the country. Two national surveys released this week suggested the same bottom line: Because most Americans believe that removing Iraqi President Saddam Hussein from power was important to U.S. security, they are willing to accept an extended reconstruction, even if that means the loss of some U.S. troops.
But opinion about the war in Iraq and its aftermath now appears far more fluid and complex than during the fighting. The percentage of polled Americans who say the rebuilding effort is going well is declining — as is the percentage who say the threat posed by Iraq justified the war.
And some experts believe that public opinion could tip against staying in Iraq if it appears that ordinary Iraqis are rejecting the U.S. presence and the mission is foundering.
That risk could be compounded if no conclusive evidence is found that Hussein was developing weapons of mass destruction.
"If weapons of mass destruction are found, that will solidify support, no matter how badly things go in the reconstruction," predicted Steven Kull, director of the Program on International Policy Attitudes at the University of Maryland.
But he added that if skepticism grows about the existence of banned weapons and American deaths continue, "those things could converge in a way that could ultimately become a negative for the president."
In a sign of shifting attitudes toward Bush's handling of postwar Iraq, some Democrats are reprising the charge they made before the war: that the president has been too reluctant to work with other nations.
"We need to stop trying to do everything by ourselves and internationalize the reconstruction of Iraq," said Will Marshall, president of the Progressive Policy Institute, a centrist Democratic think tank.
Democratic presidential candidates who backed the war also are becoming more pointed in their critiques.
Rep. Richard A. Gephardt of Missouri on Wednesday criticized comments that Bush made earlier in the day about the sporadic violence in postwar Iraq.
Bush said resistance forces hostile to the U.S. presence "feel like ... the conditions are such that they can attack us there. My answer is, bring them on."
In a statement, Gephardt said: "I have a message for the president: Enough of the phony, macho rhetoric. We should be focused on a long-term security plan that reduces the danger to our military personnel there.... We need a serious attempt to develop a postwar plan for Iraq and not more shoot-from-the-hip one-liners."
Sen. Joseph I. Lieberman of Connecticut, another war supporter among the Democratic candidates, is completing a commentary article accusing Bush of mishandling the reconstruction by delaying the transition to an Iraqi interim government and failing to give allies a large enough role in the process.
Bush declared the end of major combat operations in Iraq in a speech he gave aboard the aircraft carrier Abraham Lincoln on May 1. Since then, 66 American soldiers have died in Iraq, either in combat or accidents, according to the Pentagon. The war claimed 138 U.S. lives.
Richard Betts, director of Columbia University's Institute of War and Peace Studies, said the American public is likely to tolerate current casualty levels as long as the occupation is seen to be making progress.
But he added: "If we reach a point where more people die since Bush landed on the aircraft carrier than had died before, there will be more of an inclination to say, 'Quagmire.' "
A poll released Tuesday by Kull's group at the University of Maryland found that a majority of Americans — 53% — believed the rebuilding process was not going well.
Yet both that survey and a CNN/USA Today/Gallup Poll, also released this week, found no evidence that the concern was producing demands to reduce the U.S. commitment. For instance, just one-quarter of those polled by Gallup said the casualty levels for U.S. forces were unacceptably high.
Andy Kohut, director of the Pew Research Center for the People and the Press, an independent polling group, predicted that the public would tolerate significant casualties because it believes the ouster of Hussein was vital to national security.
"It could get to a point in Iraq where the casualties become so steady and persistent ... where people say this is out of control," Kohut said. "But there is no sign of that yet. So far, the public calculation is that the investments we've made are worth the enhanced security in getting rid of a bad guy."
Democratic pollster Jeremy Rosner, a former aide to the Clinton administration, agreed that casualties alone were unlikely to produce a public demand for U.S. withdrawal from Iraq.
"There is really a lot more evidence that the public response to casualties is to [want to] hit them back harder," Rosner said.
The failure to find weapons of mass destruction in Iraq clearly is altering public opinion on that issue. In the Gallup survey, the percentage of Americans who said they were confident that coalition forces would find such weapons dropped from 85% in March to 53% now.
As the search has dragged on, some of the Democratic presidential contenders — led by Sen. Bob Graham of Florida — have accused Bush of deliberately misleading the country about Iraq's weapons program to build support for the war.
The Gallup and University of Maryland polls found that most Americans don't now believe that charge. But in the University of Maryland survey, a majority said they believed that the administration had stretched the evidence, without overtly lying.
Another Democratic argument may find more fertile ground. In recent days, former Vermont Gov. Howard Dean and Sen. John F. Kerry of Massachusetts — two leaders in the 2004 field — and Sen. Joseph R. Biden Jr. of Delaware, who may enter the race, have called on Bush to give other nations a larger role in rebuilding and securing Iraq.
On Wednesday, Bush said he would welcome such help.
But Defense Secretary Donald H. Rumsfeld indicated this week that the United States expected relatively minor international participation in the Iraq effort.
Perhaps reflecting the growing concern over U.S. casualties, the University of Maryland survey found that nearly two-thirds of Americans want the United Nations, rather than the United States, to take the lead in creating a new Iraqi government.
For Bush, the larger question is whether the postwar problems will threaten the public consensus about the value of the Iraq war. The Gallup survey found a sharp decline in the percentage of Americans who believe "it was worth going to war" with the Hussein regime. In April, 73% felt that it was; in the new poll, just 56% did.
Times staff writer Sonni Efron contributed to this report.