An orgy of free thought? Not so likely.

I love the idea of a joint McCain/Obama town hall tour. Apparently the candidates do, too. Regular voters ask great questions, and, as the YouTube debates showed, it's harder for politicians to duck questions from them than from journalists. (They also can't complain about voters the way they can the press.) The format also lends itself to speaking in whole paragraphs rather than sound bites. Wouldn't it be great if in the age of quickly distributed video clips—which were supposed to drain politicians until they were too afraid to say more than "hello"—we had two nominees try to out-candor each other in an orgy of free thought and talk?

It would be great, but I'm skeptical. Neither of the candidates nor the parties that back them have shown much evidence that they'll let their opponent form a complicated thought in public without hogtying him to it for as many news cycles as possible.

I can see why each candidate would think the idea works for both of them. The idea of a joint free-for-all (which McCain also shopped in 2000) delights McCain both because it's unpredictable (he hates being bored) and because he's a more appealing candidate when he's talking to voters rather than delivering a speech. There are other obvious political advantages. The free publicity will be very helpful, given that McCain won't have nearly the money Obama will to pay for TV ads. And he'll either get to come across as youthful and spry next to the younger candidate—or give voters a chance to get over the issue of his age during a series of summer town halls rather than at the first debate in October, so close to election time.

There are advantages for Obama, too. If his biggest problem when matched with McCain is his gravitas, just walking on stage could help fix that. And, like McCain, Obama is appealing when he's telling us what's on his mind rather than what's on a page. These are candidates who regularly quote the books they read. They love sports. They take an ironic approach to the silly rituals of politics. Their approaches to conversation differ—McCain likes the fast give-and-take, while Obama is more professorial in his longer riffs and questioning. But both men like to do more than hand out safe thoughts in little packets. This, of course, has gotten them both into trouble—McCain countless times and Obama most recently when he mused about the motivations of small-town voters.

If the candidates really go on a joint tour, they'll be testing our capacity to hold off on our snap judgments. Will we let the candidates talk as freely as we say we want them to? Will we put a little cartilage into our politics and let them be imprecise and approximate and not jump on them with the gotchas and the Web videos? We can disdain moderators who ask questions designed to trap candidates, but we're no different if we screech every time they put a foot wrong.

There's also a test for Obama and McCain here. Both men brag regularly about their candor and how they're going to tell audiences brisk truths. That's why they both like this idea so much. It appeals to their sense of boldness, authenticity, and performance. God love them for it. But neither of them is going to have the room to tell any hard truths and explain what he means if they both keep sinking to the gotcha game-playing that makes it impossible to say anything that hasn't been pre-scrubbed.