Two things to look out for in tonight’s debate. First, will McCain dare to raise Bill Ayers? 

The fact that Obama found himself “palling around” with Ayers says less about Obama than it does about the Democratic party generally. Their view of Sixties radicals is that whatever they may have done, they were on the side of the angels and there’s absolutely no reason to ostracise them.

Should Americans care? Only if it bothers them that if Obama wins, people like Ayers will be dancing in the streets. I suspect it doesn’t, or at least not enough to influence their vote.

As a sideshow tonight, look out for the most obviously fraudulent “undecided” voter, as exposed by Michelle Malkin and others at the CNN/YouTube event last year.

We’ve had this for years in Britain on radio phone-ins where people claim to have voted Conservative all their life and then launch into a rabid denunciation of all things Thatcher. Comedy writer and Labour activist John O’Farrell in his bestselling memoir Things Can Only Get Better cheerfully admitted as much.