TAP’s Paul Waldman points to some research suggesting that conservative evangelical mobilization increases as the proportion of "secularists" in the community (county or state) rises. The author of the study works from the alleged analogy between previous white racial mobilization in the face of increasing African-American populations and evangelical mobilization in the face of increasing secularists. I think there are immense problems with the analogy (how can I tell, for example, whether my neighbor is a secularist?).
The author also argues that there isn’t a reciprocal mobilization effect for seculars. Evangelicals, in other words, behave kinda like racists in the face of seculars, but seculars don’t seem to return the disfavor. I don’t doubt that conservative seculars (at least in 1996 and 2000, the years for which the author has data) wouldn’t be more likely to vote for Bill Clinton or Al Gore as a result of the presence of evangelicals (conservative or otherwise) in their neighborhoods. And liberal seculars don’t have anywhere to go; they’ve arrived, so to speak. In other words, I could cast this data in a different light: a big tent conservatism that makes room for evangelicals and seculars doesn’t push the latter toward liberalism. By contrast, the growth of secular influence in a community (and, typically, the growth of the influence of secularism within the liberal political organization in the community) will surely provoke a countermobilization of conservative evangelicals. Big tent liberalism might moderate that effect somewhat.
I could offer also another more "pessimistic" extrapolation from this data: living together doesn’t produce mutual understanding. Is that because evangelicals are close-minded and incapable of being "enlightened"? Or because seculars aren’t good at making friends in evangelical ranks? I’d bet on some mixture of the two, without at the moment being able to argue for which in recent history came first, the close-minded evangelical chicken or the boldly aggressive secularist egg.