I think Jennifer Rubin has it right, at Contentions. McCain’s move carries fairly little risk, and the potential for real reward. Obama now looks like he’s being dragged back to Washington to do his job at McCain’s insistence, and whether the debate happens or not McCain can say that he had his priorities right and there’s no reason the country couldn’t wait a couple of days to hear them say the same things they’ve been saying for months. He should debate if Obama insists on it, but if a deal hasn’t been struck yet by tomorrow night he should say, “I’ll debate and then I’ll go back to work in Washington while you go back to talking about yourself in front of screaming fans.”
I don’t think either candidate could vote against a modified package, so if you have to vote for it anyway at least put your name on it and call yourself a hero. If a deal happens quickly (which it very well might, as soon as today or early tomorrow) McCain can say it was worth a day or two away from the trail to fulfill their actual responsibilities as senators and as nominal leaders of their parties in a national crisis, and meanwhile Obama’s rehearsal schedule is disrupted and you’ve taken temporary control of the election narrative while saving money on advertising for a few days. Why not?