Ezra Klein has a clever point about Elizabeth Warren. Republicans are blocking Warren from heading the Consumer Financial Protection Bureau. But if Warren realizes she won't get the job, she may run for Senate in Massachusetts, where she would probably be the strongest possible challenger to Scott Brown. "The obvious deal seemed to go like this," writes Klein, "Brown convinces Mitch McConnell that it’s better to have Warren running the CFPB than replacing a Republican Senator with a Democratic one."

That's the kind of deal Senate Democrats would make in a heartbeat: give some ground on policy in order to save an incumbent Senator. But Republicans don't work like that. They'll almost always trade political risk for the policy win. It's not necessarily worse, it's not necessarily better -- it's just different.