Ever since Scott Brown’s victory, he has been arguing that the Democrats health-care legislation has a higher chance of passage than most people believe. (Here’s his latest.) His argument stresses the political interests of Democrats in passing a bill that they have spent a year working on. What I haven’t seen from Chait, or anyone else, is an explanation of why it is in the individual political interest of a few House Democrats who voted no on the Pelosi bill to vote yes now. I can see why it might be in someone’s interest to flip to a no vote. But if the bill is going to pass, it needs the support of at least a few former no votes.