Not to get too meta about this, but the Christian Right's constant demands to let religion back into public life are part and parcel of the American "market" for religious experiences that Matt points out. It turns out that there are some people who like their traditional services, some people who like services with rock music, and some people who like services in which they are painted as an embattled moral minority pitted in an endless struggle against the oppressive forces of public secularism (or at least ecumenicism). Losing the culture wars is good for growing your congregation. But this argument, of course, relies on the fact that religion in American isn't publicly sanctioned. If it were, it would have an official public role, and there would be nothing to fight over. Indeed, in such a situation, you'd probably see the emergence of start-up churches arguing for a "freer" Christianity unpolluted by government intervention. "Render unto Caesar" and all that. But the folks running those churhces wouldn't be the current power brokers. Which is why, I think, you see a lot of Christians arguing for symbolic victories against the secularism of the state (more nativity scenes on public grounds, for instance) but not actually arguing for an official form of Christianity. An official form of Christianity, though way more in line with the rhetoric of "we are a Christian nation," would also make us a Christian nation that they didn't have as much of a say in. The current equilibrium, where Christianity is involved enough with the public sphere to use it for recruiting purposes but not so much as to have to cede any autonomy, is probably pretty near to optimal from a market perspective.
