My colleague Jonathan Chait has a post on the Plank about the Blue Dog Democrats and exactly how big a problem they pose. His answer: Not as big as you think. He suggests the Blue Dogs are simply waiting, because they don't want to take a tough vote (raising taxes, etc.) on health reform before they are certain the Senate will do the same.
This isn't a fundamental clash over ideology. It's a skirmish over the timing of a vote. The Blue Dogs don't want to have to vote for a more liberal bill than what ultimately becomes law. A lot of the fighting we're seeing a a result is probably kabuki theater. The real bounds of reform will beset by the Senate.
I'm not sure I'd go quite that far: Plenty of Blue Dogs have serious reservations about health reform. And for some of them the concerns are substantive. They're more liberal than Republicans but still more conservative than many Democrats.
But the broader point here is absolutely correct. It's highly unlikely that reform fails to pass because of the House. Whatever the Blue Dogs think, House Speaker Nancy Pelosi almost certainly has the power to force a vote--and to make sure it's a "yes" vote--if she chooses to exercise it. She has at her disposal myriad tools for reward and punishment.
So what does this mean? It means, as Jon says, that the fate of health reform lies in the hands of the Senate, which--for the moment--means it lies in the hands of Max Baucus and Charles Grassley. What a great governing system, huh?