Obama, obviously, has to say what he has to say. And a case can be made that his explanation for bipartisanship -- that it's a "bad habit" that can be changed -- is an elegant way of signaling disapproval without admitting defeat. But there's still something galling about it. Last night, after Gregg withdrew his nomination, Senator Claire McCaskill twittered -- yes, twittered -- "old ways die hard around here. I know our President won't give up on changing the unproductive partisan habits." This isn't victimless rhetoric: Suggesting that partisanship is a "habit" -- like drinking milk out of the carton -- cements the sense that partisanship is a trait. It's not. It's a question of political incentives. Of disagreements. The Republicans are right to assail the stimulus. Betting on its failure is their most obvious path back to power. Trying to block its progress and lessen its impact is the straightforward way to weaken Obama's presidency. But that means actively working to disrupt a real response to the recession. Those incentives don't change unless the voters change them. And voters won't change them in they don't have to face them. Arguing that partisanship is a habit -- a sort of political squabble that would end if everyone simply ceased acting like children -- obscures the actual contours of the problem. It's leaves voters disgusted with the amorphous concept of Washington rather than concerned with the realities of the system. It may be good rhetoric for Obama, but it's bad rhetoric for change.