Via ActBlue, Blue America has raised nearly $200,000 for members of Congress who have pledged to vote against any bill that doesn't contain a public option. Pretty impressive. If push comes to shove, and the choice is no bill vs. a bill without a public option, I sort of hope these guys all break their word and vote for it anyway. (Or at least enough of them, anyway.) But my preferences aside, this is a pretty good way of solving a big problem for the public option supporters: how do you make a threat to vote No credible when everyone knows liberals are champing at the bit to pass healthcare reform? Well, this is one way. It's a lot harder to make a U-turn and vote Yes after taking a very public stand against it and then accepting a bunch of activist money based on giving your word to stand firm.1
1Which isn't to say they won't do it anyway. These are politicians, after all, and thus capable of just about anything. But it's definitely harder.
UPDATE: Ezra Klein says my email explanation of the point I was making was much clearer than my actual post. So here it is:
The Blue America money helps make the promise to vote against any bill without a public option more credible. Right now, no one believes it. Everybody thinks that, in the end, liberals will cave and vote for it regardless. But with this money in place, which is going to people on condition that they vote against any bill without a public option, it makes it genuinely hard for them to turn around and vote Yes after all. It helps turn a meaningless threat into a credible one.
CORRECTION: This money was raised by Blue America. ActBlue is just the conduit. The text has been corrected to reflect this.