Republican groups that support same-sex marriage want to send a message to their party's voters and candidates: We are not an anomaly.

Two right-leaning groups—American Unity Fund and Project Right Side—are releasing a poll that they say shows that most voters support gay marriage, and a higher proportion of Republicans support gay marriage than measured before.

"‹The poll surveyed 2,000 registered voters nationally by phone this month, including 798 Republican and lean-Republican voters, along with 500 voters in the early primary states of Iowa, New Hampshire, Nevada, and South Carolina.

The poll found that 57 percent of all registered voters favor legalizing gay marriage, and 59 percent of voters said they would accept the Supreme Court's forthcoming decision on same-sex marriage as the law of the land, even if that means accepting legal same-sex marriage nationwide. Of Republican voters surveyed, just 39 percent favor legalization, and 44 percent said they would accept the Supreme Court's ruling.

That may not seem like much Republican support, but it represents a significant shift for the party over the past few years. Between 2011 and 2014, Project Right Side found that Republicans supporting full legal rights for gay couples jumped from 14 percent to 25 percent. The latest poll found that 43 percent of Republicans believe gay couples should have the same rights as straight couples.

These groups hope their data on Republican voters will convince party leaders that, even if they personally disagree with same-sex marriage, it's no longer an issue worth fighting. To Republican groups such as American Unity Fund and Project Right Side, same-sex marriage isn't a question; it's a foregone conclusion. 2014 was an historic year for gay rights, with marriage equality laws going into effect in 19 states.

"Our goal is to persuade every single Republican in America that it is conservative to be for full freedom and equality for LGBT Americans," said Margaret Hoover, the president of the American Unity Fund.

American Unity Fund—a 501(c)(4) nonprofit group—was started by Paul Singer, a billionaire hedge fund manager, with the purpose of supporting Republican candidates who back same-sex marriage both politically and financially. In 2014, the group's affiliated super PAC, American Unity PAC, spent $4.7 million to help Republican candidates.

The groups say that while Republicans are still coming around to supporting same-sex marriage, it's a growth industry among younger voters. Roughly three-quarters of all voters ages 18 to 34 support same-sex marriage, along with 61 percent of millennial Republican voters.

Still, most of the Republicans running for president in 2016 have vocally opposed same-sex marriage. Dr. Ben Carson once compared gay marriage to pedophilia and bestiality (and now says he will no longer talk about it). Louisiana Gov. Bobby Jindal, who announced his presidential campaign Wednesday, has said he will remain firm in his opposition to same-sex marriage. Former Arkansas Gov. Mike Huckabee went as far as to warn his party against tacking left on the issue at the risk of alienating social conservatives.

Republicans in some parts of the country are more open to same-sex marriage than others, making the primaries a difficult tightrope for GOP contenders to walk. In New Hampshire, a majority of likely Republican primary voters—58 percent—said gay and lesbian couples should have the right to marry. But other early primary states saw less support among Republican voters: 47 percent in Iowa, 45 percent in Nevada and 39 percent in South Carolina said they support same-sex marriage.

But Samantha Artley, a Republican pollster for Target Point Consulting, said such views are getting pushed out of the mainstream in her party whether candidates like it or not.

"Republicans that are homophobic don't have a place in the party," she said. "Republicans that believe in traditional marriage, that's their right and those are their values, and that's important that they can keep those values. But they need to understand that tolerance and acceptance is also important."

The Republican groups that favor same-sex marriage hope politicians will follow suit.

When the Supreme Court rules in Obergefell v. Hodges—the same-sex marriage case—presidential candidates on the right and the left will have to comment on the decision. Hoover says her group wants to show Republicans that, like the failed constitutional amendment after Roe v. Wade, calling for a constitutional amendment banning same-sex marriage is not a political winner. Her group isn't looking for Republicans to greet an affirmative ruling with cheers; for now, she'd settle for a shrug.

"I think anybody's persuadable," Hoover said. "Do I think that they'll come out in favor of the freedom to marry before 2016? Probably not."

Update: This story has been clarified to note that American Unity PAC only donates to Republican candidates.

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