Just two years ago, Colorado’s House Republican leadership felt so strongly about fighting off legal recognition for same-sex relationships that they twice torpedoed a civil unions bill that otherwise was guaranteed passage on the floor.

The world has changed drastically since then — and so has the approach by the state GOP’s standard-bearers to the once-divisive topic.

Take Bob Beauprez, Cory Gardner and Mike Coffman, all opponents of same-sex marriage and all locked in tight races.

The Republican candidates for governor, U.S. Senate and U.S. House, respectively, reacted with a rhetorical shrug Oct. 6 when the U.S. Supreme Court refused to hear a bundle of state appeals of rulings striking down their same-sex marriage bans. The action effectively legalized gay marriage in Colorado and a bevy of other states.

Not long ago, the result would’ve been a political earthquake. Colorado’s new gay marriage reality once was a prospect that drove fearful voters to the polls, as when they passed the state’s now-invalid constitutional ban on same-sex marriage in 2006. Back then, Colorado’s Republican members of Congress frequently co-sponsored the Federal Marriage Amendment to ban gay marriage everywhere.

But ahead of the Nov. 4 election, gay marriage now is an apparent non-issue.

GOP insiders and political analysts say Colorado Republicans’ rapid tone shift — which still meets resistance from some social conservatives — is necessary for their political survival.

In the last three years, polls have gone from showing the state’s voters evenly split on gay marriage to favoring it by a solid majority — as high as 61 percent. Republicans remain divided in polls, though most support at least civil unions.

“It won’t be that many more election cycles before this issue is a dead horse, even within Republican primaries,” predicted Eric Sondermann, a Denver-based independent political analyst.

Seeing GOP shift up close

Colorado Log Cabin Republicans vice president Alexander Hornaday, a Denver attorney, has seen the rapid change up close, both in private conversations and at public events. The group represents gay conservatives.

At the Republicans’ 2012 state assembly, he recalled, the group’s chapter president gave a speech casting support for same-sex unions as a conservative position and was met with some boos. Party chairman Ryan Call delivered a reprimand to the crowd.

This year, Hornaday addressed the state assembly on the group’s behalf, and “I heard nothing but cheers.”

More recently, he says he’s talked about October’s Supreme Court action with high-placed Republican officials who publicly oppose same-sex marriage. He’s heard them express not disappointment, Hornaday said, but relief that the courts have taken the issue off the table.

“There is quick movement within the Republican Party to recognize we have a diversity of views on gay rights,” Hornaday said. “And increasingly, the party is moving toward being accepting and being proponents of gay rights.”

Movement on marriage has happened so fast that even some Colorado Democrats, including Gov. John Hickenlooper, Beauprez’s opponent, have come around to supporting same-sex marriage vocally only in the last year, as it became clear it was a winning issue.

All told, recent court decisions have expanded the number of states allowing same-sex marriage from 19 to 32, plus the District of Columbia. More than 60 percent of the U.S. population lives in those states, and three more, including Kansas, will be added soon.

Beauprez reacted to the Supreme Court’s recent action by saying he’d enforce all of Colorado’s laws while calling for respect for religious institutions’ constitutional right to recognize only “traditional marriage.”

Coffman, a congressman in suburban Denver being challenged by Democrat Andrew Romanoff in a highly competitive district, said in a debate that night: “The courts have spoken, and I respect the decision.”

And Gardner’s statement, while reiterating that “My views on marriage long have been clear,” said people should honor the courts’ decisions. The congressman is challenging Democratic U.S. Sen. Mark Udall.

Gardner also said: “Coloradans are tired of politicians who spend all their time on partisan hot-button issues that divide our state.”

All three struck a tone and used the kind of phrasing that many Republicans nationally have chosen.

“What we’re seeing is that candidates and legislators are recognizing that good people can disagree on these issues, and they’re also sensing that public opinion has shifted dramatically over the last few years,” said Jeff Cook-McCormac, senior adviser to Washington, D.C.-based American Unity Fund. The group, launched by big GOP donor Paul Singer, focuses on lobbying Republicans to support gay marriage and related issues.

Some GOP faithful reject change

But while the debate has shifted nationally, it’s not over. Some big-name Republicans have decried the rulings on gay marriage, including Kansas Gov. Sam Brownback and 2016 presidential aspirants such as Texas Sen. Ted Cruz.

In Colorado, too, the GOP still has some catching up to do.

While party spokesman Owen Loftus says the party hears little from the rank-and-file about gay marriage, the party’s platform resolutions, adopted in April, include one saying: “It is resolved by Colorado Republicans to support and defend the definition of marriage as the union of one man and one woman.”

That item was approved at April’s state assembly by a nearly 5-to-1 margin.

And some elected officials and Republican candidates vow not to back down or accept that the Supreme Court’s action likely brings finality to the gay marriage fight in Colorado.

But what they can do is unclear.

“I’m wrestling with where we go from here, because in many ways I think the government has completely turned a blind eye to reality,” said state Sen. Kevin Lundberg, who’s running for re-election in his Berthoud district. He’s not giving up. “For me, I’m going to take a very vocal stand against the cowardly actions of the Supreme Court.”

Though gay rights have gotten little attention in this year’s general election, they did come up forcefully in some Republican primaries, particularly in two Jefferson County state senate races in which social conservatives beat moderates.

The most visible target was Mario Nicolais. He had served as the spokesman for Coloradans for Freedom, a group of Republicans, many of them straight, that lobbied for civil unions in 2012 and again in 2013, when the Democrat-controlled legislature finally passed the bill.

Nicolais faced an onslaught of mailers from social-conservative groups and the Rocky Mountain Gun Owners on various red-meat issues. All were motivated, he suspects, by his support for civil unions and now marriage equality. He lost by a 33-percentage-point margin to Tony Sanchez, who’s now challenging Democratic Sen. Andy Kerr.

While analysts say gay marriage could surface again in primaries, a Public Policy Polling survey released Oct. 21 provided more evidence of the continuing shift in favor.

The poll of likely voters reported that 54 percent overall said gay marriage should be allowed, with 39 percent opposed and the rest undecided.

It found that Colorado’s conservatives view same-sex marriage more complexly, and voters older than 65 are the only age group in which a plurality still opposes marriage rights.

Among Republicans, same-sex marriage support was at just 30 percent. But add in civil unions, which Beauprez backs, and support for recognition of some kind increased to 68 percent.

Among “very conservative” voters, support for same-sex marriage recognition still was very low, at 8 percent. But support for recognizing either same-sex marriage or civil unions reached a combined 50 percent.

“That is a sea change,” Sondermann said, “when the far flank of the spectrum has moved to some sort of a 50/50 proposition.”

Jon Murray: 303-954-1405, jmurray@denverpost.com or twitter.com/JonMurray