CONCORD, N.H. – Whether they like it or not, Republican presidential candidates are joining New Hampshire’s intensifying gay marriage debate.

State lawmakers plan in the coming weeks to take up a measure to repeal the law allowing same-sex couples to wed and a vote is expected at some point in January — the same month as New Hampshire holds the nation’s first Republican presidential primary contest.

Already, candidates have been put on the spot over the social issue when most, if not all, would rather be talking about the economy, voters’ No. 1 concern.

The impending focus on gay marriage carries risk for several of the White House contenders — including Mitt Romney, Rick Perry and Herman Cain — whose inconsistencies on the topic are well documented.

The GOP candidates’ support for “traditional marriage” also threatens to alienate a growing number of younger Republicans and independents here who support legal recognition of same-sex couples. That note of divisiveness could bode poorly for the eventual GOP nominee come the general election.

Even so, the Republican candidates aren’t shying away from the topic as they run for the nomination of a GOP dominated by conservatives and pushed further to the right by the tea party over the last few years.

“I applaud those legislators in New Hampshire who are working to defend marriage between one man and one woman realizing that children need to be raised in a loving home by a mother and a father,” Perry told a New Hampshire audience recently, becoming the latest contender to address gay marriage directly.

While the issue hasn’t yet become a talking point on the campaign trail, most GOP candidates declare support for the effort to repeal the law.

Romney was the Massachusetts governor when his state legalized gay marriage. HIs administration, as directed by the courts, granted nearly 200 same-sex marriage requests for gay and lesbian couples in 2005.

Campaign spokesman Ryan Williams said Romney had little choice but to follow the state Supreme Court ruling at the time. He noted Romney’s consistent opposition to both civil unions and gay marriages, adding that Romney openly supports the New Hampshire repeal effort.

But Romney has reversed himself on whether gay marriage should be addressed at the state or federal level.

This past June, he said at a debate that he favors a federal constitutional amendment banning the practice. That’s been his position at least since the start of his 2008 presidential bid.

But as a Massachusetts Senate candidate in 1994, he told Bay Windows, a Boston gay newspaper, that “the authorization of marriage on a same-sex basis falls under state jurisdiction.”

Aides say it’s unfair to scrutinize his position in 1994 — when there was virtually no discussion of a federal amendment.

Both Perry and Cain have drawn conservative criticism for recent comments related to gay marriage.

Asked in mid-October whether he supports a federal marriage amendment, Cain told the Christian Broadcasting Network that federal legislation is necessary to protect traditional marriage. That seemed to directly contradict his statement of just six days earlier, when he told “Meet the Press” host David Gregory that states should be allowed to make up their own minds.

Perry says he supports the New Hampshire repeal. But in July he said that New York’s move to legalize gay marriage was “fine by me.” A week later, facing social conservative criticism, he walked back the comments.

“It’s fine with me that the state is using their sovereign right to decide an issue. Obviously gay marriage is not fine with me,” he said then.

Former House Speaker Newt Gingrich has another problem.

Earlier this fall, he told Iowans that gay marriage is likely to go away because it defies convention. Gingrich, who has been married three times, has a half sister, Candace Gingrich-Jones, in a same-sex marriage.

“You’re living in a world that no longer exists,” Gingrich-Jones wrote Gingrich in a letter posted on the Huffington Post in 2008. “In other words, stop being a hater, big bro.”