when the cockroaches start jumping overboard you know the boat is sinking fast.
Excatly right. The MSM can spin this a positive for Pelosi all they want, but this just adds to the sense that the Democrats are sinking, and fast - that perception amongst the members of her own caucus will doom Obamacare.
Here's how I see it - if you're a Dem who walked the plank for Nancy in the first vote, and you know your constituents are mad about it, and you expect to be in the minority in the fall if you survive, anyway - well then, why not improve your chances of reelection and vote no?