A Senate committee's approval of a resolution authorizing military force against Syria gave some momentum to President Barack Obama's effort to win overall congressional support for the effort, but conference calls involving members of his own party indicate that it's still an uphill battle in the House.
With Obama in Sweden and Russia trying in part to rally global backing to punish Syria for its alleged use of chemical weapons, his chief of staff briefed two Democratic blocs -- the solidly anti-war liberal Congressional Progressive Caucus and the Congressional Hispanic Caucus.
Several members who participated in the calls indicated the administration still has a lot of work to do.
"If I had to vote today, I would vote no," Missouri Rep. Emmanuel Cleaver told CNN.
Cleaver noted he had multiple concerns before Wednesday's call, which occurred on the same day the Senate Foreign Relations Committee approved a resolution authorizing a limited military strike on Syria.
The administration says there is overwhelming evidence that Bashar al-Assad's regime killed more than 1,400 people in a chemical weapons attack earlier this month outside Damascus, violating global conventions against their use, further escalating a two-year civil war, and putting civilians and allies in the region at new risk.
A key question
Cleaver didn't dispute the evidence, but asked a question that others have posed over the past two weeks.
"What is the U.S. position -- do we react militarily when people get murdered with sarin gas? Do we respond when people are slaughtered in Darfur when sarin is not used?" he said.
Cleaver, the former head of the Congressional Black Caucus, said he's willing to listen to a classified explanation, but the case hasn't been made yet.
"What form of slaughter is more repugnant?" he asked.
The Congressional Black Caucus is scheduled to meet with National Security Adviser Susan Rice in a closed meeting on Monday, a caucus spokeswoman said.
No doubt, Cleaver will hear from constituents on the issue when he holds a town hall meeting at home in Kansas City on Thursday evening.
Although Obama has appealed to congress to act for the good of humanity, polls show that most Americans surveyed do not want the United States to intervene in the Syrian conflict, which the United Nations estimates has claimed more than 100,000 lives.
The administration, working with Congress, has said it is planning for a limited strike, which experts believe would involve cruise missiles.
Senior officials have said there are no plans to involve American combat troops, a restriction reinforced by the Foreign Relations Committee resolution that has yet to be considered by the full chamber.
Another Democrat who listened to the call, Illinois Rep. Jan Schakowsky, also agreed that the evidence was convincing that the al-Assad regime used weapons against its own people.
But in a statement to CNN after the call Schakowsky, who sits on the intelligence committee, said the information so far was helpful but not sufficient.
"As much as I need to consider the scope and duration of any attack, I have many questions about its efficacy," Schakowsky said. "I want to know to know what evidence the administration can provide that this strike will denigrate the Assad regime's ability to use these weapons again, what plans have been made for possible retaliation and a clear sense of the end game."
Iraq a factor
The U.S. experience in the protracted and costly Iraq war weighs heavily on House Democrats, and many are pushing to include specific limitations on the length and scope of any military mission.
Many members of Congress also remember the faulty intelligence that underpinned the U.S. rationale for invading Iraq a decade ago.
One senior Democratic aide who participated in the White House call with Hispanic members said there remains a broad spectrum of questions about the need for military action against Syria.
But "for those that are on the fence the resolution has to be as limited and tailored as possible before they will vote for it," the aide said.
Senior House Democratic aides cautioned that it's still premature to gauge the votes, and said the vast majority of House Democrats are still undecided and asking for more information.