Nancy Pelosi knows how to count votes.

House Minority Leader Nancy Pelosi

From her most ardent allies to her most vitriolic opponents, there is a widespread recognition that when she says she can deliver votes from the Democratic caucus, she can deliver the votes. Remember the health care bill. (This is, it's worth noting, a striking contrast to the struggles that House Speaker John Boehner has experienced in trying to rally his fractious conference behind him on everything from the fiscal cliff to the farm bill.)

That reputation faces a massive challenge as Pelosi (and the White House) try to bring the lion's share of House Democrats into line behind the use of force resolution against Syria.

The numbers are stark. Pelosi is one of just 11 House Democrats who are on the record in support of the resolution at present. By contrast, 23 Democrats are on the record opposing the measure.

Pelosi herself has acknowledged the difficulty in securing a majority of House Democrats to support the Syria resolution. "I don't know," she said when asked whether it would pass by Time Magazine. "I think it would be important to get a majority in the Congress. But I don’t know if it’s important how you would break it down. These issues are not really partisan.”

Maybe not. But to have the resolution come even close to passing the House -- given the significant (and growing) opposition within the GOP -- the White House is going to need some large-ish segment of liberal Democrats to support it.

Enter Pelosi. The key to understanding her power within her caucus -- and the impossibility of anyone dethroning her as the top-ranking Democrat in the House until she decides it's time to say goodbye -- is her influence among liberals who now comprise a clear majority within House Democratic ranks. (The 2010 elections thinned the herd of moderate and conservative Democrats significantly.) When Pelosi talks, liberals listen. And that's why she has been able to deliver time and again on tough votes.

"Many of her members will listen to her because she led the opposition to the war in Iraq and she shares their skepticism about getting into another ground war," said Brendan Daly, a former top aide to Pelosi. "But she has said that preventing the spread of chemical weapons is a pillar of our foreign policy and she supports this as a limited, humanitarian intervention."

Daly added that Pelosi has said she will not be actively whipping the vote and has called it a conscience vote -- meaning that laying expectations on her for its passage -- as some Democrats critical of the White House believe the president is doing -- is unfair.

"She is irrelevant with regards to this vote," said one Democratic strategist sympathetic to Pelosi. "With the intervention in Syria being so unpopular and polling very low across the country, House Democrats will not forsake their constituents just for Democratic unity in Washington."

Other Democrats point out that Republicans are in the majority and, therefore, need to be held more responsible for delivering the votes on a measure like this one that does not divide down the typical partisan lines.

Still, the path to a majority in the House appears to be this: Establishment and hawkish Republicans + lots of Democrats loyal to Pelosi and/or Obama. At the moment, that equation isn't close to adding up -- and it's not clear whether Pelosi, or anyone else, can change it.