There was a weird moment in one episode of the ABC's Kitchen Cabinet last year.
The host, Annabel Crabb, was being treated to a barbecue by shadow treasurer Joe Hockey. The conversation turned to Hockey's view on gay marriage. He restated that he was opposed. Okay, fine. But then he admitted that it was probably inevitable: Australia will allow two people of the same gender to marry eventually, regardless of what he thought about it.
This is not how conservatism is supposed to work. William F Buckley famously (and sympathetically) described a conservative as someone who stood athwart history yelling ''Stop!''
On gay marriage, the conservative mainstream is now just standing to the side, watching the world rush by, with a sort of hapless resignation.
It must be strange to know you are on the wrong side of history. And Hockey's position seems to be a common one. It's not a position that says gay marriage is inevitable yet subsequent events will prove it to be a mistake. No, it seems to be more that gay marriage is both inevitable and inconsequential.
Perhaps, as the great conservative philosopher Michael Oakeshott once wrote, change simply has to be suffered.
On gay marriage at least, social conservatism has suddenly shifted from being a political asset to a liability. This was most illustratively shown during the Senate confirmation of Chuck Hagel as Barack Obama's secretary of defence in January.
In 1998, Hagel was a senator for Nebraska and on the other side the confirmation process. He criticised one Clinton ambassadorial candidate for being ''openly, aggressively gay''. This little episode was dug up during Hagel's confirmation this year as evidence that he was a secret bigot.
That's fair enough. But Hagel's contemporary critics have tried to pretend that such showy political homophobia was rare, when it was distressingly common until very recently. Clearly, elected politicians of the time believed making anti-gay statements was of political benefit. This is no longer the case.
The gay-marriage-is-inevitable line has swept through American conservative circles. Even Rush Limbaugh — possibly the world's most famous shock jock — says conservatives will have to get used to the fact they have lost the debate. Many conservatives have gone further and actively embraced marriage reform.
The Australian right has been slower than its American counterparts. But it's happening. Malcolm Turnbull now backs gay marriage. You'd probably expect that. Turnbull is a small l-liberal who enjoys swimming slightly out of the pack. But he had been coy about the whole thing for a very long time.
More interesting was the declaration of support earlier this month by Kelly O'Dwyer — Liberal member for Higgins, former Peter Costello staffer, and one of those recent parliamentary entrants who everybody says is leadership material.
It is hard to imagine there being any serious political cost to O'Dwyer's position. Over half of self-identified Coalition voters support gay marriage. The South Australian Liberal Senator Simon Birmingham, who announced his support all the way back in November 2010, looks less like an outlier and more like a forerunner.
In a famous speech in 2011, David Cameron said he supported gay marriage not despite the fact that he is a conservative but because he is a conservative. That wasn't just the cheap rhetoric of a politician. The conservative argument for marriage is compelling and convincing. A happy couple in marriage is an absolute good, individually and socially and financially.
The evidence suggests marriage offers specific, concrete benefits to those who pursue it. Extending it to same-sex couples should be a no-brainer.
And we shouldn't pretend that traditional marriage is some unchanging, unbroken institution now under existential threat. Rush Limbaugh is wrong to say that conservatives have lost the argument because they have allowed the word marriage to be ''bastardized and redefined''. Marriage has always been bastardised and redefined.
This important paper by the Australian writer Helen Dale for the American free market think tank Reason Foundation shows that human history has had many different ideas about the purpose of marriage.
One particular point is well made. Modern opponents of gay marriage claim that marriage has historically been about procreation. This sounds plausible, at least until you recall the extreme levels of infant mortality in past eras. As Dale writes, ''children were by no means guaranteed''.
Most attempts to divine a universal core in the idea of marriage are unhistorical. So allowing same-sex couples to enjoy the benefits of this institution is less radical than it first seems.
Proper conservatism understands that tradition reflects deeper truths; that the social institutions we have inherited have proved their merits by their own survival. Monogamous marriage is one of those institutions. Age is a virtue, not a flaw.
This makes conservatives reluctant to embrace radical change. But in the rush to defend marriage strictly as it is, conservatives have forgotten what makes marriage so beneficial. Those benefits have nothing to do with gender. To actively support gay marriage — not to powerlessly regret it — is unambiguously the most conservative approach.