The first debate was at podiums and the second debate was townhall-style. Tomorrow's debate will be the sit-down variety, where the moderator and the two candidates share a table. I like the fact that the three debates are done in three different styles because it gives the voter a variety of perspectives by testing the candidates in different ways.

The sit-down style of debate is the most intimate and is generally thought to be the least conducive for personal attacks. There are several psychological reasons, for both the candidates and the viewing audience, why this is thought to be the case. It's much harder to level a personal attack at someone's face than it is when you are directing your remarks to a camera, a studio audience, or the moderator. From the viewer's point-of-view, it is perceived as rude to insult someone with whom you are sharing a table. For these reasons, sit-down debates tend to be both more chatty and more amiable. It won't be possible for McCain to repeat his performance from debate one, where he refused to acknowledge Obama's presence. And if he tries to repeat his stunt from debate two, referring to Obama as 'that one', it will come off very badly, indeed.

The topic of discussion for the third-debate will be domestic issues and, chief among them, the economy. That doesn't mean that Schieffer won't address any current issues in the campaign, though. There could be questions about William Ayers or ACORN or Sarah Palin's violations of the law or the thuggish behavior of the McCain-Palin supporters. Unfortunately for McCain, the format is not conducive to advancing his recent lines of attack. In a sense, the McCain-Palin efforts have been aimed at dehumanizing Obama, making him out to be mysterious, foreign, and radically out of the mainstream. But there is nothing more humanizing than sitting down at a table and having a chat about important issues.

If you've watched much in the way of Sunday morning political programs, you've probably noticed that senators tend to maintain a respectful decorum when you sit them down next to each other. It goes with the culture of the institution in which they serve. This common courtesy can be frustrating to partisans, but any breach in that protocol is jarring. People expect senators to disagree, but respectfully.

These circumstances put John McCain in quite a spot. His manhood has repeatedly been called into question, including by Barack Obama himself. As a result, John McCain has promised to bring up the issue of William Ayers, even though it can in no sense serve his interests to do so. This will be, after all, a debate that is largely focused on the economy and other pressing domestic issues. If McCain is very lucky, Bob Schieffer will raise the issue himself and give McCain an excuse to defend his honor by maliciously savaging the honor of his opponent. If Schieffer does not provide McCain with a natural in to bring up the wholly irrelevant Ayers, McCain will be compelled to shoehorn the issue into an answer to a question that is totally unrelated.

Either way, McCain will have to perform some kind of Jedi mind-trick to avoid giving the impression that he is an insufferable, out-of-touch, grumpy sore loser when he talks about William Ayers. And the same can be said of almost all of his campaign-trail talking points. McCain will score no points for rudeness, and he'll be eviscerated for passivity. He's painted himself into a box and the format allows for no easy route of egress.

Barack Obama, on the other hand, simply needs to maintain the high road. What could be easier than that?