I don’t know why we need any religious leader delivering an invocation at a President’s inaugural.

I thought we’re supposed to have separation of church and state in America.

But the custom persists, and Obama announced on Wednesday that the Reverend Rick Warren would be giving the invocation on January 20.

This has understandably ignited a firestorm of protest from Obama’s progressive base.

For one thing, Warren is anti-abortion.

For another, he threw his considerable weight behind Proposition 8, outlawing gay marriage in California.

Warren likened it to incest, child abuse, and polygamy.

The victory of the forces of intolerance in California struck a cruel blow to gays and lesbians not only there but around the country.

And Warren played no small part in it—and in other campaigns against gay marriage.

So why in the world is Obama inviting him to bless his inauguration?

During the campaign, Obama felt the need to genuflect before Warren in a town hall meeting with McCain.

He was under no obligation to do so then, though he considered it politically expedient. Just as he considered it politically expedient to saddle up with homophobic black ministers in South Carolina early in the campaign.

But he certainly was under no obligation to bend his knee and kiss the ring of Rev. Warren now.

Obama is doing so because he’s a placator. He’s got a bad habit of playing to the crowd, and of peddling post-partisan bromides that render real politics meaningless. If you say, as Obama just did on Thursday, that “I am a fierce advocate for equality for gay and lesbian Americans,” and then you blather on about your desire for “a wide range of viewpoints,” as he went on to do, how fierce an advocate are you really?

Joe Solmonese, president of the Human Rights Campaign, called Obama’s choice of Warren “a genuine blow to LGBT Americans.” He added, “We feel a deep level of disrespect when one of the architects and promoters of an anti-gay agenda is given the prominence and the pulpit.”

Obama made a serious blunder on the way to his Inaugural, which Warren is already in the process of marring.