Nate Silver on why the left is suddenly unified behind the bill:
Personally, I think the reason for the increase in support is mostly this: the Democratic leadership, and particularly President Obama, are now fighting for this bill tooth and nail. They didn't necessarily have to do this; they could have thrown in the towel, passed off some bipartisan crap that didn't do much to help the uninsured, and called it a day. That's what Rahm Emanuel wanted to do, as Chris Bowers points out. But that isn't what Obama did: instead, he's gone all-in on the thing, potentially staking his Presidency on the outcome. Liberals like the idea of being the scrappy underdog -- being the fighter -- and Obama, after a strangely aloof performance on the health care bill throughout 2009, has been fighting the good fight.
But look what's happened to moderates too. Obama's measured performance these past two months, his civility and his outreach to the GOP has won them over as well as the liberals. And the right has become more isolated this year.