The closest thing Congress has to a peace movement - 71 liberals who want to yank Iraq funding and bring troops home swiftly - faces a dilemma: The lawmakers can back a Democratic plan they think is too weak, or they can block it and risk an embarrassing defeat for their cause.
It falls to one of their strongest allies, House Speaker Nancy Pelosi, D-Calif. - whose San Francisco district is passionately against the war - to persuade them to accept a less aggressive stance.
Pelosi is working feverishly to scrounge together enough Democratic votes to pass a war-spending measure that would force the withdrawal of combat troops from Iraq by 2008. Leaders circulated a draft Monday, and the House is set to weigh in on it as early as next week.
The 'Out of Iraq caucus
Many of the liberals, who sometimes refer to themselves as the "Out of Iraq" caucus, are adamantly opposed to the funding bill in any form. They argue it would prolong the war,and are angry that leading Democrats are not pushing for a quicker withdrawal.
"There's a significant number of people who are steadfast in not continuing this war, who absolutely don't want to fund the surge and who want to give a voice to the people who voted on Nov. 7 and asked us to end this once and for all," said Rep. Lynn Woolsey, D-Calif., a leader of the Progressive Caucus.
Voters are "asking us to be bold. They're begging us to take action," Woolsey said.
But with conservative and moderate Democrats refusing to consider a faster timetable or a cutoff of war funding, party leaders have had to steer a more centrist course on Iraq.
They point to polls that show the public opposes cutting off funding or revoking President Bush's authority for the war but backs bringing home troops by next year. They argue that their measure can at least make Bush report to Congress any time he deploys a unit that doesn't meet training or readiness standards, or has not spent at least a year at home between tours.
'If you push too far, you may get nothing'
Some left-of-center Democrats say they recognize their party's delicate position, and are coming around to the idea of supporting an Iraq measure that falls short of what they want.
"If you push too far, you may get nothing," said Rep. Jerrold Nadler, D-N.Y. "I'll be attacked by people at home saying it's not perfect. It's not. We don't have the votes to pass something that's perfect. It's the best we can get."
More unbending, vocal core members of the group - represented in recent days by Woolsey and California Reps. Maxine Waters Barbara Lee, among others - are standing resolutely against the rest of their party.
They have aired their concerns in the press and in closed-door gatherings with House leaders, meeting for hours with Pelosi in her Capitol office last week to press their case.
"She's one of them. She certainly understands their concerns," Pelosi's spokesman, Brendan Daly, said. "This isn't just an exercise or a theoretical argument. We want to pass something, and this is the strongest bill we think we can get approved."
Liberals 'screwing it up'
Progressives' uncompromising stance - and that of the liberal groups that back them - has invited some derision within Democratic ranks that has bubbled over in public.
Rep. David Obey, D-Wis., was captured on camera by an anti-war group telling activists who confronted him outside his Capitol Hill office that "idiot liberals" don't understand Democrats' strategy for leaving Iraq. In the video, widely circulated on the Web, Obey says liberals are "screwing it up" for lawmakers trying to find the votes to end the war.
Obey, an irascible 37-year House veteran, has since apologized for the comments, saying in a written statement that the confrontation was "just another example of how Americans have become needlessly and painfully divided" on the war.
Other Democrats argue that progressives are voicing legitimate concerns but ultimately must bow to political reality.
"This is an issue that they have embraced very specifically, and they are speaking from their hearts and frankly expressing the feelings of many Americans, but we have to govern - we're in the majority now," said Rep. Ellen Tauscher, D-Calif., a moderate.
Betraying constituents and defying the base
The progressives' frustration at being asked to compromise to appease the more conservative elements of their party is palpable.
"You have some people here who are fearful of doing what even they know is the right thing," said Rep. Maurice Hinchey, D-N.Y. But Hinchey, too, said he would back the party's Iraq proposal.
"I deeply regret it, but you have to face the reality that in order to step forward and do anything, we've got to bring 218 people together," he said, referring to the number of votes needed to prevail in the 435-member House.
While progressives like Woolsey worry that Democrats are betraying their constituents and defying their base, many strategists and analysts argue that their core supporters ultimately will forgive the party for moderating its stance on Iraq, given that the alternative in the 2008 elections will be Republicans who have consistently backed Bush.
Liberals "are taken for granted, and that's why they're making all this noise and threatening to make real problems for the party," said Jeffrey M. Berry, a Tufts University political scientist. "In the end, those problems are tiny as you compare them against the ghost of George Bush."