David Adesnik writes:

But when it comes down to getting votes, I think there are only two questions that really matter: Did Bush ignore (and then withhold) compelling evidence that Al Qaeda was preparing a major attack? And did Bush knowingly lie about Iraq’s possession of chemical and biological (not nuclear) weapons? Unless Clarke can answer one or both of those questions in the affirmative, his revelations won’t amount to much more than a very loud footnote.

I think that’s just about right.

Update: Dan Drezner has a roundup and a more expert reaction.

One thing I will say: the sum total of my international relations training is four graduate courses, and my scholarship focuses on mass political behavior (public opinion, voting behavior, political parties, things like that) and legislative behavior, not IR theory or practice. I’ll defer to Dan and James Joyner on the substance of IR policy—though, to the extent the discussion has an impact on electoral politics or public opinion, I’m probably a decent judge.