Clinton, who supports a timetable for withdrawing troops from Iraq, spoke three hours into the Armed Services hearing, “fundamentally” disagreeing with the threats made by McCain, his Republican allies and Petraeus.

“I think it could be fair to say that it might well be irresponsible to continue the policy that has not produced the results that have been promised time and time again at such tremendous cost to our national security and to the men and women who wear the uniform of the United States military,” Clinton said. “The lack of political progress over the last six months and the recent conflict in Basra reflect how tenuous the situation in Iraq really is.”

“I also think that the surge has reduced violence and provided breathing room, but that breathing room has not been taken the way we would all like it to be taken,” Obama said.

But as the debate raged in the hearing rooms, behind the scenes, Democrats started to pave the way for this year’s Iraq debate.

At a closed luncheon Tuesday, Senate Democrats debated proposals that could add pressure for Bush to change course on the war, including a plan by Sen. Ben Nelson (D-Neb.) to require that U.S. money for Iraq reconstruction be made as a loan for the country, rather than a grant, and Sen. Jim Webb’s (D-Va.) proposal to improve educational benefits for veterans of the wars in Iraq and Afghanistan.

Democrats are considering adding the Webb proposal to a fiscal 2009 defense authorization bill, the first vehicle for this year’s Iraq debate that will come to the Senate floor before Memorial Day, according to Senate Majority Leader Harry Reid (D-Nev.).

Reid planned to meet with House Speaker Nancy Pelosi (D-Calif.) on Tuesday in the first in a series of meetings to hash out bicameral Democratic strategy on Iraq.

Reid said debate over the future of the war would also occur when Congress takes up the war supplemental, totaling  about $109 billion. Democrats will try to add language to stimulate the economy, including an extension of unemployment benefits and provisions to encourage summer jobs.

Reid also said that Congress would have to review carefully an agreement that will be unveiled this summer stating the United States’ commitment and role in Iraq, saying it cannot be binding on the next president.

At the hearing, Crocker said unlike a treaty, the agreement would not be sent to the Senate for ratification since it will contain no binding requirements.

“We do not intend to provide any binding commitments that would trigger the advise-and-consent process with the Senate,” Crocker said.

That prompted a sharp rebuke from Clinton, who in a measured tone said it was “odd that the Iraqi parliament may have a chance to consider this agreement, [but] that the United States Congress would not.”

When his turn came, McCain asked Petraeus and Crocker specific and brief questions.

“There are numerous threats to security in Iraq and the future of Iraq,” McCain said. “Do you still view Al qaeda in Iraq as a major threat?”

“It is still a major threat, though it is certainly not as major a threat as it was, say, 15 months ago,” Petraeus said.