What did he know and when did he know it?

"I never thought I'd hear this question raised in my lifetime again, but the question really now is going to become 'what did the president know and when did he know it?" former Vermont governor Howard Dean, referring to the Watergate scandal that led to the resignation of President Richard Nixon, told reporters at a fundraiser for Iowa Gov. Tom Vilsack.

Graham told reporters the Bush administration had engaged in a "pattern of deception and deceit."

"I hope that we'll find weapons of mass destruction in Iraq because the failure to do so will be an enormous blow to our credibility abroad and among the people of America," he said.

"We put our valiant men and women in harm's way ... under what appears to have been at least less information than the American people deserved," Graham said.

Kucinich, long a critic of the war, accused Bush aides of pursuing a "fraudulent" foreign policy.

"They never had the information that they told the American people they had to justify going to war," Kucinich said, adding that Democrats had to challenge Bush on the issue to ensure he did not use the same tactics to justify sending troops into Iran and Syria.

Lieberman, one of the co-sponsors of the resolution authorizing the war, said there had been reason to believe Saddam had weapons of mass destruction.

"Very serious questions are being raised now about whether our intelligence community had it right, whether the administration was over-stating the case," he said.

"It ought not diminish from the fact that our military did what was right in overthrowing Saddam and the American people are safer as a result of it."