The idea that we should trust Kerry, even if we think his previous foriegn policy instincts have all been bad, because he has nothing to gain from failing to pursue Al Qaeda, makes little sense. Surely George Bush had nothing to gain from failing to suppress the insurgency in Iraq, and yet his administration still hasn't done so. This argument seems to fall into the partisan assumption that if Kerry fails it will be out of malice. But most people who think that Kerry isn't the right man for the job think he will fail not because he wants to, but because he's fundamentally wrong in some way in his national security strategy.But Sullivan shouldn't be taken that seriously. He's merely grasping at excuses for his anti-Bush stance, which is predicated on Bush's opposition to gay marriage.
Similarly, it doesn't strike me as very logical to imply that Democrats have abandoned national security issues, and then suggest electing them anyway as a way to force them to "take responsibility" for national security, any more than I would employ a drug addict in a pharmacy on the theory that this would force him to "take responsibility" for enforcing our nation's drug laws.
P.S. Mike Rappaport of The Right Coast seems to agree with my diagnosis of Sullivan's real issue with Bush.