Listening to Andrew Cuomo castigate social conservatives and imply that they're not welcome in New York really brings back memories for me. And not happy ones.

Back in the early '90s, I (temporarily) became a conservative, bolting from the centrist liberalism in which I was raised, in part out of exasperation at the political correctness of the Left at the time. It was the heyday of multiculturalism, when all that seemed to matter was where you came from and how well you could emote about your origins. As long as you weren't a white male, that is. In my high-minded (white male?) way, I believed that where you came from mattered much less than where you were going — and where I wanted to go was in pursuit of timeless ideals of truth, goodness, and beauty.

Thanks to my only partially adequate reading of Allan Bloom's Closing of the American Mind, I naively came to believe that the Right was a much more suitable launching pad for that idealistic intellectual pursuit. That's one explanation for how I ended up as an editor at First Things magazine, a journal that's aptly been described as the New York Review of Books of the religious right.

Before long, though, I began to realize that what the magazine stood for was just another form of identity politics. America, you see, is essentially a Christian nation, and that's what it's been from before the time of the founding. And not just Christian — conservative Christian, religious right Christian, late 20th-century Republican Party Christian. Members of that tribe were the only true Americans. Others — whether non-conservative Christians, non-Christian religious believers, or secularists — were less capable of being good citizens, less fully American, and maybe even (in some ill-defined sense) un-American.

So much for truth, goodness, and beauty.

Eventually, I returned to the center left I had embraced in my youth, hoping that the multicultural fever of the '90s had broken. And for a while it seemed like it had. The opposition to George W. Bush and then Barack Obama's post-racial campaign for president in 2008 were both broadly universal in aspiration.

But since then things have deteriorated, with the movement for gay marriage (which I support) serving as an occasion to turn ideology, once again, into an identity marker. Do you support gay marriage? If so, then you are One Of Us. If not, you must be a homophobic bigot. And bigotry has no place in Enlightened America. So get the hell out.

Until a few days ago, dear reader, you would have responded to those last few lines by dismissing them as inflammatory right-wing propaganda. No actual liberal, no champion of tolerance, no defender of freedom of thought and worship, would ever dare say such a thing. Right?

Wrong. As everyone now knows, New York's Democratic Gov. Andrew Cuomo fashions himself a bouncer stationed at the door of an exclusive nightclub called The Liberal State (Proprietor, John Rawls). And he wants social conservatives to know that their kind aren't welcome on the premises. Opposed to abortion and gay marriage? Then kindly get lost.

Even if Cuomo said what he said merely to whip up enthusiasm among rich liberal donors — actually, especially if he said it for that reason — he deserves to get his political ass handed to him. Cuomo just turned a movement for civil rights into an expression of tribalism and effectively excommunicated millions of his fellow Americans and New Yorkers, relegating them to the status of second-class citizens.

It may be news to Andrew Cuomo, scion of Democratic Party royalty, but social conservatives aren't resident aliens in the United States, granted political freedoms solely at the pleasure of right-thinking politicians. America is as much their country as it is his.

When liberals play by the rules of identity politics, drawing lines to determine who's in and who's out of the club, they fall far short of their own highest ideals.

They also set themselves up for failure. It's only a matter of time, after all, before their political opponents win an election and set out to exact revenge by casting them into civic outer darkness. And round and round it goes.

God help us all.