Timothy Egan on American politics and life, as seen from the West.

How do you praise the sanctity of traditional heterosexual marriage when the best-known nuptials of the year, between a Kardashian and a basketball player, lasted all of 72 days? Or, for that matter, when a possible Republican nominee for president, Newt Gingrich, cares so much about marriage that he’s tried it three times?

Molly Riley/Reuters

You don’t. The above mockeries of marriage are just the latest reasons one of the most potent wedge issues of American politics — the banner of gays, guns and God — will have little impact next year.

This trio is usually trotted out in big swaths of the West, in rural or swing districts and in Southern states at the cusp of the Bible Belt. The proverbial three G’s was the explanation in Thomas Frank’s entertaining book “What’s the Matter With Kansas” for why poor, powerless whites would vote for a party that promises nothing but tax cuts for the rich.

It’s misleading to think people will vote against their economic interests simply because a candidate doesn’t mouth the same pieties as they do. But the cultural cudgel works to a point. I’ve certainly seen the three G’s launched late in a campaign, to great effect. Jim Inhofe won a Senate seat in Oklahoma in 1994 using the three G’s as an overt slogan.

At the same time, I’ve watched smart politicians, like Montana’s two-term Democratic governor, Brian Schweitzer, blunt the attack by showing off their guns and waving away the God and gay questions as none-of-your-business intrusions.

But this year I think we’ve reached a tipping point on these heartless perennials. When George W. Bush won re-election in 2004, political sophisticates were stunned by a national exit poll in which 22 percent of voters picked “moral issues” from a list of things that mattered most — more than any other concern. This was heralded as the high-water triumph for evangelicals.

Later analysis showed that the phrase “moral issues” was being used rather broadly by voters, from concern about character to worry over poverty. It was a catch-all. Still, the ranking of moral issues as the top reason to pick a president came as a surprise.

Now look at this week’s New York Times/CBS News Poll of likely Republican caucus-goers in Iowa, about as conservative a cohort of voters as anywhere in the country. Iowa, for Republicans, is where gays, guns and God will grow in political fields long after corn is no longer planted for ethanol subsidies.

Topping the list of voter concerns was the economy and jobs — picked by 40 percent of respondents, followed by the budget deficit at 23 percent. Social issues came in a distant third, with 9 percent. And the candidate who polled highest as the one who “most represents the values you try to live by,” Michele Bachmann, has nothing to show for that rating in the overall race, where she is in fifth place.

But the decline of the three G’s hasn’t stopped a few of the dead-enders in the Republican field from raising the flag. Gov. Rick Perry of Texas, last seen trying to find a verb to follow “oops,” is out this week with a very specific culture-war ad in Iowa, vowing to end “Obama’s war on religion,” whatever that is.

“I’m not ashamed to admit that I’m a Christian,” says Perry, in a folksy drawl. “But you don’t need to be in a pew every Sunday to know that there’s something wrong in this country when gays can serve openly in the military, but our kids can’t openly celebrate Christmas or pray in school.” The surprise here is that he actually completed several sentences, though it may have required a number of takes.

Perry and Rick Santorum, another badly wounded culture warrior, blasted Secretary of State Hillary Clinton this week for saying that the United States would assist human rights groups fighting for tolerance in countries where people have been imprisoned, and even killed, for their sexual orientation.

“This administration’s war on traditional values must stop,” said Perry, siding, apparently, with mullahs living in caves.

This is Perry’s last gasp; in desperation, he shows how this particular balloon has run out of hot air. Poll after poll has found that Americans now overwhelmingly favor letting gays serve openly in the military — a sentiment backed even by a sizable majority of Republicans.

The gay marriage issue is moving in the same direction. Earlier this year, Gallup reported that, for the first time in its tracking of the issue, a majority of Americans believe same-sex marriage should be legal. In 1996, only 27 percent felt that way.

Which brings us to guns. President Obama has done nothing to curb gun use. If anything, he’s expanded gun rights. There are probably a dozen Democrats in Congress from the West who know more about guns than Mitt Romney or Professor Newt Gingrich. That dog, as they say, will not hunt — not this year.

The irony is that two of the G’s could actually hurt Republicans in 2012. Conservative orthodoxy is badly out of step with emerging majority support for full citizenship rights of gays. And with religion, some Republicans have already made an issue of Romney’s Mormonism, and Gingrich’s switch to Roman Catholicism. In Gingrich’s case, questions have been raised about how a multiple-married man could win the favor of high-ranking Catholic clerics who usually look askance at people who ditch their wives.

Do we dare expect these two fine men to be the ones, at long last, to bring an end to the gays, guns and God wedge issue, even if it’s by accident?