In her column today, Gail Collins notes:
Since Obama, the Commission on Presidential Debates and the University of Mississippi, which is hosting the debate, all say it will go on, it isn’t clear what will happen if McCain fails to show up. An empty chair? A last-minute invitation to Ralph Nader and Bob Barr to drop on by? Once in New York, when Rudy Giuliani boycotted a mayoral debate, one of his opponents spent the night twirling around a rubber chicken and the citizenry enjoyed it quite a lot. This isn’t the kind of thing you could imagine Obama doing, but I’d keep my eye on Barr.
That seems something of a stretch to me. Barr hasn't made nearly the inroads into the public debate that I imagine he thought he would. So here's the question: If McCain doesn't show up, who should Obama debate?