News from the front has been decidedly mixed in the past week, but the unexpectedly gloomy reports have not shaken public support for the war in Iraq, according to the latest Washington Post-ABC News poll.

Nearly three out of four Americans continue to back U.S. actions to remove Iraqi President Saddam Hussein from power -- even though they have come to believe that there will be "a significant number of additional U.S. military casualties." If anything, that support may be hardening: The poll found an increase in the number of respondents saying they "strongly" support the war.

For President Bush, the public's backing is a sweet note amid the rising chorus of criticism over the U.S. invasion strategy and the awkward diplomacy that led up to the war. It is almost an article of faith at the White House that Bush has forged a bond of trust with a majority of Americans since the Sept. 11, 2001, terrorist attacks on the United States. As long as he appears steadfast, the president and his aides believe, he will hold on to a solid base of support that can carry him through rocky times.

Nancy Broome is a good example of the sort of person Bush is counting on. She finds herself watching the news from Iraq and thinking that the president has been right all along.

"He made it very clear that this was going to take some time," said Broome, 42, from her home in Salisbury, N.C. If she made any mistake, she said, it was in not listening to him closely enough. "I think everybody thought it would be as easy as Desert Storm -- speaking for myself, that's what I thought -- even as Bush was saying, 'this will take time.' "

Public fears of a bloody conflict have soared in recent days. The number of respondents who expect "significant" additional casualties more than doubled in one week, to 82 percent. The survey found that hopes for a quick end to the war have largely vanished in the face of growing Iraqi resistance, miscues on the battlefield and swirling sandstorms that grounded allied aircraft for several days this week and slowed down the ground invasion. Nearly six in 10 said they believe the war will last months rather than days or weeks, a view expressed by less than half of those interviewed four days earlier.

Four in 10 said it is likely that the United States will become bogged down in a drawn-out war with Iraq, and one in four said it was a "mistake" to attack Iraq.

But those views have not shaken support for the war. The results challenge -- in a very preliminary way -- the long-standing belief among many political analysts that Americans cannot endure protracted conflict or the sight of body bags. Even among respondents who said that the number of U.S. casualties in Iraq is already "unacceptable," a majority continued to express support for the war.

Ditto for those who said it is likely that the United States will get bogged down in Iraq. In this group, 57 percent expressed support for the war. That is much lower than the 86 percent support among people who said such a messy involvement is unlikely -- but a clear majority nonetheless.

Eric Uslaner of the University of Maryland has studied the effects of public opinion on foreign policy. He, too, expects public opinion to be steady for the foreseeable future, giving Bush some room to breathe.

"Generally, the public rallies around the president during a crisis," he said. "And, even if people expect the war to go on for months, it takes a long time for public opinion to turn sour. It would take a much longer period of time, and much more disastrous outcomes, for the public to turn against the president at a time of national crisis."

Backing the war does not mean, however, lockstep support for everything Bush proposes. On the home front, Americans strongly agreed with this week's Senate action to slash the president's proposed tax cut. Two in three respondents -- Republicans, Democrats and independents alike -- favored the Senate plan to reduce Bush's $726 billion tax cut by more than half to help pay for the war, shore up Social Security and reduce the deficit. Nearly three in 10 wanted the tax cut eliminated entirely, the poll found.

For 30 years , the shadow of Vietnam has hung over U.S. discussion of war and peace, especially in government and academic circles. One lesson that is often drawn is that the public can turn sharply against a war if the price in blood grows too steep or the going gets too difficult.

But it may not be blood or hardship alone that turns the tide. John Mueller, author of "War, Presidents and Public Opinion," notes the importance of "good results" in the equation.

History offers some confirmation of that. Abraham Lincoln prosecuted the bloodiest war in American history and got nowhere for more than two years. The Civil War quagmire soured public opinion, and Lincoln's reelection prospects appeared doomed -- until the Union army finally began winning battles in the summer of 1863. When Gen. William Tecumseh Sherman captured Atlanta two months before the 1864 election, public support for Lincoln surged and he won a second term in a landslide.

According to Uslaner, the reason public opinion hardened against the Vietnam War -- and, before that, against the Korean War -- was that the enemy was not clearly defined and the mission was not understood. Ultimately, there were not enough "good results."

"In both Korea and Vietnam, as casualties mounted there was an increase in belief that the war was a mistake," Mueller explained. "People tend to make this into a cost-benefit analysis." If they see few benefits in a war, they begin to focus on the costs exclusively. On the other hand, a clearly understood benefit, like avenging Pearl Harbor, can outweigh quite terrible costs.

For some poll respondents, the fact that the Iraq war is proving difficult actually brings the potential benefits of victory into sharper focus -- which could help explain why support for the war seems to have stiffened. They blame Hussein, not Bush, for the bloodshed.

Michelle Decker was one. "I think the war is going fairly well," said Decker, 34, of Seabrook, Tex. "Obviously, we'd like to see no casualties on our side, but that's not possible. We're starting to see how underhanded [the Iraqis] are. I can't believe they're willing to put women and children in the line of fire."

Tim Leslein, 30, of Columbus, Ohio, agreed. If anything, he said, Bush needs to push harder. "I think they need to . . . put the hammer down."

But for the one-quarter of Americans who oppose the war, the sometimes grim news of the past week underlined the idea that dissent is not the same as a lack of patriotism or concern for the troops. Barbara Boies, 55, of New York said everyone should be moved to stop and think when they see images of troops under fire -- most of them for the first time in live combat. "I don't think supporting America means I have to go along with this," she said.

A total of 508 randomly selected Americans were interviewed Thursday night for this survey. The margin of sampling error for the overall results is plus or minus 5 percentage points.