For the first time since the United States invaded Iraq a year ago, the nation is evenly divided over the war.
That drop in support for war (to a 49-49 percent split) is a significant change from just two months ago when 65 percent of those polled by The Gallup Organization thought the war was worthwhile and 33 percent did not.
There are several reasons for this watershed in public opinion: steadily rising US casualties (539 killed and 3,030 wounded at last count), the inability of US forces to prevent massive car-bomb attacks, an increasing portion of the public that does not feel particularly threatened despite color-coded terrorist alerts and the recent ricin episode on Capitol Hill, and growing concern about domestic issues. Recent polls, for example, show the economy to be just as much of a worry as the threat of terrorism - and in some cases, a bigger concern.
So far, the chief stated reasons for invading Iraq - unconventional weapons on hair-trigger alert, a clear connection with Al Qaeda, the notion of Americans being welcomed as liberators, and the idea of Iraq as a pathway to Middle East peace - have not materialized in any clear way.
"The overriding issue is the expectation-reality mismatch," says retired Air Force Col. Sam Gardiner, who teaches at the National Defense University. "The war was supposed to be quick. We were supposed to be greeted as liberators. It was to pay for itself with oil revenues. And we were supposed to find chemical and biological weapons."
Recent testimony by chief CIA weapons inspector David Kay and Secretary of State Colin Powell confirmed the likelihood that no such weapons existed on the eve of the US invasion.
"It is clear that Kay's comments have had a profound effect on public opinion," says Daniel Goure, national security expert with the Lexington Institute in Arlington, Va. "Americans want to be winners, but they also want to be right," he continues. "There is a sense that we were wrong."
Not surprisingly in a presidential election year, President Bush's political opponents are encouraging this change in public opinion.
But not all criticism of administration assertions on Iraq is from the left.
Conservative broadcaster Bill O'Reilly this week said he had been wrong to accept official claims that Saddam Hussein's regime had weapons of mass destruction. "I think all Americans should be concerned about this," said Mr. O'Reilly of Fox News, who pronounced himself "much more skeptical about the Bush administration now."
Added to this, the White House appears not to have scored as highly as it hoped to by agreeing to the hour-long live interview in the Oval Office, broadcast last Sunday on NBC's "Meet the Press."
Peggy Noonan, a speechwriter for former President Ronald Reagan, described Bush's interview as "not impressive." "He did not seem prepared," Ms. Noonan wrote on the Wall Street Journal website. "He seemed in some way disconnected from the event."
Given the diplomatic run-up to the US invasion of Iraq, the lack of formal United Nations approval, and the opposition of many traditional allies, the year-long war - with its mounting US casualties and slow pace of rebuilding - is seen by many Americans as primarily Mr. Bush's responsibility. His casting himself as the "war president" reinforces that image. Questions about his National Guard service some 30 years ago may be detracting from his image as Commander in Chief and thereby weakening public support for the war as well.
So when Bush's political standing begins to dip, it's logical that support for the war - which peaked at 76 percent when Baghdad fell last April - might wane as well.
Two polls last week may indicate this: A Newsweek poll had Bush's approval rating down to 48 percent. A simultaneous Associated Press/Ipsos poll showed just 44 percent of respondents believing the country is headed in the right direction, with 52 percent saying it's on the wrong track. A Christian Science Monitor/TIPP poll completed this week gives Bush a moderately positive reading - 53.5 - in its presidential leadership index, but well below the 58.8 mark he enjoyed after Mr. Hussein's capture.
The unusually high number of National Guard and Reserve troops now on active duty - and growing concern of family and friends - adds to public discontent about the war. "Many service members signed up for the duration of the peace, and now find themselves in a war with no end in sight," says John Pike, director of GlobalSecurity.org.
Thirty-five years ago growing opposition to the Vietnam War caused significant changes in US policy there. And public opinion today may be having a similar impact.
"The political problems caused by the war and casualties in Iraq have already had their biggest impact on conduct of the war: abandonment by President Bush of the neoconservative goal of reshaping the Middle East through running Iraq for several years," says Marcus Corbin of the Center for Defense Information in Washington. "The turnover of some authority to Iraqis in June may or may not lead to a rapid reduction in US influence and troops in Iraq, but it certainly signals the end of the neoconservative dream."