[Re-posted from earlier today.]

Last week, as regular readers know, I went to the University of Idaho to debate whether civil marriage equality was good or bad for society as a whole. My interlocutor was and is a fundamentalist, a believer in Biblical morality, and a very hospitable and gracious host. I had dinner with his extended family – an impressive, funny, intelligent crew. His son-in-law friend, who shepherded me around, was super-smart, is obviously fully engaged in the modern world, educated and eager to chat. He also believes that the earth was created in six days six thousand years’ ago, that civil marriage should be reserved for heterosexual couples only, and that abortion should be illegal.

I just want to say I wish I met more Christianists like this more often. My hosts sincerely believe that there can be no solid separation between church and state and no basis for social order or “truth” other than Biblical morality as strained through the New Testament. And so purely pragmatic political arguments can quickly become problematic for them. Peter Leithart, who attended the debate, wrote it up on First Things and admirably homed in on the core divide:

Sullivan demanded that Wilson defend his position with secular, civil arguments, not theocratic ones, and in this demand Sullivan has the support of liberal polity. Sullivan’s is a rigid standard for public discourse that leaves biblically-grounded Christians with little to say … That leaves Christians with the option of making theologically rich, biblically founded arguments against gay marriage. But do we have the vocabulary ready to hand? And even if we do, does the vocabulary we have make any sense to the public at large? Wilson closed the debate with a lovely sketch of the marital shape of redemptive history, from the garden to the rescue of the Bride by the divine Husband to the revelation of a bride from heaven. In order for that to carry any weight, though, people have to be convinced that social institutions should participate in and reflect some sort of cosmic order. Who believes that these days? Wilson tells a cute story, many will say, but what does it have to do with public policy? If that’s a hard case to make, it’s even harder to make the case that homosexuals are in any way a threat to our civilization.

Rod Dreher notes:

This is the answer to the question about “cosmic” versus “moral.” Leithart is pointing out that the metaphysical ground has radically shifted under our feet. The traditional Christian moral arguments depend on a metaphysical understanding that is no longer widely shared, not even by Christians.

This is why Christianism cannot win a majority – and is fast becoming a smaller minority. If your agrument is that God says so – and your fellow citizens don’t believe in that same God – how can you even engage in secular debate? New analysis (pdf) of polling and the last election results on the gay marriage question, for example, reveal that only one major religious group now opposes marriage equality across the board: white evangelical Christians, who are pretty close to synonymous with the Tea Party. Even every other Christian population supports it! From white non-evangelical Christians to Catholics, clear majorities favor the reform.

To give one comparison: white Catholics back civil marriage equality by 53 – 43 percent. Hispanic Catholics back it by 54 – 35. But white evangelicals oppose it by a massive margin: 73 percent oppose it, 23 percent support it. The GOP’s problem is that this is their base; it cannot compromise because God’s word is inviolable; and yet it is also losing the argument badly. You either stick with this base and lose – or you fight them and lose. Which is why so many in the GOP are now just not talking about the issue.

In Idaho, the crowd was largely white and evangelical. They voted overwhelmingly against marriage equality at the start and after a debate in which my opponent conceded that his argument was ultimately rooted totally in Biblical truth and not secular consequences, and who declared the state of heterosexual marriage as in crisis. In other words, that night mirrored the last twenty years. The longer this debate has gone on, the more the opposition has withdrawn to claims of simple Biblical authority. That is not an appeal to the center of the American polity. It’s a withdrawal from it.

The theo-conservative response to this was an attempt to revive “natural law” arguments against gay marriage, derived from updating Aquinas. But deriving an “ought” from an “is” in nature has been deeply problematic since Hume. And if you were going to do that anyway, I think you’d have to concede that we now know empirically that same-sex attraction among humans and most other species is ubiquitous, and may even have some kind of evolutionary advantage. Aquinas didn’t know, for example, that humans were conceived by a woman’s egg as well as a man’s sperm. He couldn’t possibly have known what Darwin and his followers have unfolded: a vast, constantly shuffling of DNA, designed to generate diversity in order to survive the challenges of subsistence through time and environment. He couldn’t have known that the animal kingdom is full of homosexuality; or that gender can change in fishes (see the blue-banded gobies above); or that grasses have many genders; or that countless human beings are born with indeterminate gender or trans-gender.

My view is that if you take Aquinas’s core position in 2013 – and try to deduce what is right from nature itself – you’d probably have to conclude that homosexuality is itself a natural deviation from the norm, and that such deviations are not “mistakes” but, if they survive the test of scores of millennia, are actually integral to nature. Aquinas saw through a glass darkly; now we see gene to gene.

So we end up in David Bentley Hart’s words here:

If we all lived in a Platonic or Aristotelian or Christian intellectual world, in which everyone presumed some necessary moral analogy between the teleology of nature and the proper objects of the will, it would be fairly easy to connect these facts to moral prescriptions in ways that our society would find persuasive. We do not live in such a world, however.

But we still live in a democracy. Which means that this worldview cannot survive in our culture and polity without some massive Third Great Awakening that shows no sign of emergence in the developed world. The natural law Deus Ex Machina, in other words, either leads to believing that homosexual orientation is natural or collapses in the civil sphere because of previous concessions and loopholes: no fault divorce, contraception, women’s greater freedom and power, the acceptance of infertile couples and post-menopausal couples as civilly married. The only argument they have left is the nebulous idea that this will all somehow lead to polygamy. But there are very good civil and secular arguments against polygamy – the subjugation of women, the social consequences of large numbers of young men without women to marry, etc – that cannot apply to allowing gays to marry. Almost all the utilitarian, pragmatic arguments against marriage equality evaporate upon inspection. And it remains a truth that the attempt by Popes John Paul II and Benedict XVI to revive this tradition and win back the West to neo-Thomist doctrine has been a total failure.

They cannot even persuade their own flock, let alone the rest of society. We are left in the world Alasdair Macintyre brilliantly laid out many years ago. If the democratic conversation has to continue without universally shared concepts of the divine order, it must do so with pragmatic, secular and civil arguments. They may be rooted in faith, but they cannot appeal to mere divine authority to persuade.

Which is why the Christianists are losing – and so suddenly. My hope is that this failure will help many of them either to seek their own salvation and leave others be (a long evangelical tradition in America before liberal over-reach in the 1970s) or to re-learn how to engage in civil, secular argument. But that won’t be easy. And it may simply be far too late.

(Photo: blue-banded gobies from Wiki; painting of Thomas Aquinas by Fra Bartolommeo, also via Wiki.)