You've probably read Virginia Postrel's NYT article on work on religion and politics by Ed Glaeser and his students (one of whom, Jesse Shapiro, I've met through IHS), but I just wanted to point out just how important this stuff is if it's on the right track. They give a structural explanation for the apparent increase in the religiosity of politics at a time when religious participation is declining. They argue that there is an optimal group size for rhetoric targeted at the extremes of the political spectrum and the size of religious groups in the US now close to optimal.
While outsiders may know something about a candidate's more extreme positions, group members know more – because the messages are aimed specifically at them.
“When I go out and say, 'I want to tax all the rich and I want to end outsourcing,' I can give that message to an economically left-wing audience without the economically right-wing audience hearing it with exactly the same probability,” Professor Glaeser said. “All you need is some ability to target your message, and then you're going to go to extremes.”
Those in-group forums work, however, only if the groups are just the right size. They have to be small enough to be homogeneous and big enough to be influential. “The model has this very odd prediction that the power of social groups is most when they're roughly 50 percent of the population,” Professor Glaeser said.
If a group is too small, it's not worth courting. But if it's too big, it includes too many of your opponent's supporters, making targeted messages impossible. If everybody goes to church or belongs to a union, membership in either group will not predict voting behavior.
The fascinating upshot seems to be that if trends in the religiosity of the population continue, the kind of targeted messaging Rove & Co. have been using with such success may become obsolete. The seemingly deep divisiveness of the Red State/Blue State sham may be nothing more than a hiccup of demography, and all this hair-pulling clamor about learning to talk to the churchy folk may be beside the point.