With President Obama set to deliver a speech embracing his approach to deficit reduction, my question is, why now? I agree that the medium term deficit is a serious problem. I'm willing to accept some painful social spending cuts. What I don't understand is the administration's apparent determination to address the problem right away.

The first problem with trying to get a bipartisan agreement now is that the sanity of the Republican party is at a nadir. Coming out of the 2010 elections, Republicans are riding a wave of ideological and political confidence, and Democrats are panicking. Just as you wouldn't want to find your lifelong mate right after a painful breakup, this is a terrible time to be setting long-term budget priorities.

Second, Democrats will obtain massively greater leverage after 2012. As I've argued, if Obama refuses to accept another extension of the Bush tax cuts on income over $250,000, then Republicans will kill the entire Bush tax cuts for him. That would change the entire course of the budget debate. Restoring Clinton-era revenue levels won't be a huge concession wrested from Republicans at the cost of horrible social policy, it will be a fait accompli. If Obama wants to make another deficit deal after that, maybe reforming the tax code in the process, he can knock himself out. And making a deal coming off a win is likely to find the GOP is a more chastened -- or, at least, less insanely triumphal -- mood.

Now, there is an argument for making a deal now. A bipartisan agreement would cast Obama as a pragmatic centrist, and improve his standing with independents, regardless of the unpopularity of the substance of the proposals. (Most voters follow broad heuristics rather than substance, which is why the contentious, drawn-out health care reform law was unpopular despite the popularity of most its provisions.) Yet that same reason suggests why Republicans will be so hard to deal with. They don't want to take one of their strongest issues off the table for the 2012 reelection. The GOP will drive a hard bargain, forcing Obama to sign off on damaging long-term policies.

Obama can cut a better deal in 2013. He should gesture toward bipartisanship, and explore the possibility of a decent bargain should one open up, but he should not put himself in a position where the failure to reach a deal is his problem. Indeed, his persistent habit of letting legislative failure be his failure has maximized the GOP's leverage against him. That's a mistake he has to stop making.