So yesterday, John McCain attacked Barack Obama for lacking specifics. Also yesterday, McCain's economic advisor, Kevin "Dow 36,000" Hassett attacked Obama for allegedly pilfering Clinton's economic stimulus program. (The criticism, and Obama's denial of it, can be found here.)

I noted yesterday that it's odd McCain would be attacking Obama for lacking specifics, when McCain is far vaguer and more ill-informed than Obama. It's even odder that McCain's campaign is jumping into the question of which Democrat came out with which stimulus plan first. I expected MCain to go after Obama, I just thought it would be on grounds of being a liberal liberal liberal peacenik.

Could the answer be that... McCain's goal is not to hurt Obama in the general election but to hurt him in the primary? Every poll now shows Obama performing better than Clinton against McCain. On average, he does five and a half points better than her, which is a very significant margin.

So it's quite likely that the reason that McCain is amplifying Clinton's attacks on McCain, rather than make attacks that would fit his general election audience, is that they're targetted to the primary. If McCain attacks Obama for wanting to withdraw from Iraq, that helps Obama in the primary. If he attacks him for lacking domestic policy proposals, it helps Clinton. I suspect McCain is trying to pick his opponent here, the way Richard Nixon tried to sink Ed Muskie's primary campaign in 1972, but without the illegality. (I'm not suggesting there's anything immoral about the tactic -- if I were McCain I'd do the same thing.)

--Jonathan Chait