I completely understand why Andrew is upset by Obama's choice to have Rick Warren deliver the inaugural invocation. As Andrew points out, Warren sides with Christian orthodoxy in opposing gay marriage, and he has refrained from condemning the Bush administration's policy on torture. Both of those are major issues for Andrew.
But Obama's a politician, and the Warren pick is just the latest sign that he's an exceedingly shrewd one (as Andrew concedes). Warren is beloved by mainstream evangelicals, who have helped him to sell millions of books extolling a fairly anodyne form of American Protestantism. (Pat Robertson or Jerry Falwell he is not.) It is in Obama's interest (and the Democrats') to peel as many moderate evangelicals away from the GOP as he can. Giving Warren such a prominent (but purely symbolic) place in the inauguration is a politically cost-free way of furthering this partisan agenda. (As for whether having Warren deliver the invocation is an example of "Christianism," I'd only note that Obama didn't start the tradition of including prayers in these civic occasions. And his own speech is guaranteed to be more restrained in this regard than others have been.)
Now, Andrew might be right that Obama will not prove to be a champion of gay civil rights (at least when it comes to the issue of marriage). But we can be absolutely sure that no presidential candidate of the current Republican Party would be anything other than a rabid opponent of these rights. And that means: What benefits Obama and the Democrats -- and what harms the Republicans -- contributes (if perhaps only negatively) to Andrew's cause. And that should be what counts.
Click here for Damon's take on Rick Warren and the "end" of the culture wars.