Check out this explanation for McCain's interesting "tick".
While we are on the topic of American politics, obviously there is a lot of interest both down here and I presume back home in the Biden vs. Palin match-up tomorrow night (interesting side note - I wonder how many Canadians are going to choose the American VP debate over the Canadian English debate?). Everyone I have been chatting with here (in, I grant you, one of the most "liberal" zip codes in the entire United States) thinks Palin is going to be a complete disaster. As a former debater, I am not so sure. Not only are expectations ridiculously low for her, but I think this analysis by Dahlia Lithwick is right on the money. In particular, her point about it being easier to debate a good debater than a bad debater is a very important one.