"People listen to debates because they care about the issue. And they only care about the issue because they've already taken a side. Caring then innoculates them to reason."

This conflicts with my personal experience so badly, I'm not sure what to make of it. When I see pamphlets for debates at my local university campus, the only ones that sound exciting are ones that both sides of the debate sound reasonable. Also, I have changed my mind about important political issues twice as the result of listening to a debate. Obviously, this is simply anecdotal evidence, but without showing me some kind of data on the subject I will continue to trust my own experience.