The McCain camp tells Mike Allen that Palin will go after Joe Biden tonight, trying to catch him out on old foreign policy positions that didn't pan out. Right. I don't buy that because I don't think they want to risk getting her into any detailed discussion of any foreign policy or defense issue. What strikes me as much more likely is that they'll send her in with a handful of prefab digs or snark lines. Their hope would be that whatever comes out of the debate itself -- that some clever or incendiary snark line will dominate the next day's news cycle and get the campaign coverage on to some Obama-Biden shortcoming rather than on Palin being an imbecile and McCain looking like he's about to go postal.