WASHINGTON — For more than a year House Republican leaders have insisted the chamber would act on new immigration laws. And for more than a year, Republicans have done virtually nothing on the issue — despite intense pressure from activists, business groups, and the nation's changing demographics.

And although there are a variety of reasons for inaction, one Republican lawmaker recently offered a frank acknowledgement that for many House Republicans, there's one issue at play that's not often discussed: race.

"Part of it, I think — and I hate to say this, because these are my people — but I hate to say it, but it's racial," said the Southern Republican lawmaker, who spoke on the condition of anonymity. "If you go to town halls people say things like, 'These people have different cultural customs than we do.' And that's code for race."

There are a range of policy reasons for opposing plans to liberalize immigration or to regularize undocumented immigrants in the country, ones revolving around law-and-order concerns and the labor market. But that perceived thread of xenophobia, occasionally expressed bluntly on the fringes of the Republican Party and on the talk radio airwaves, has driven many Hispanic voters away from a Republican leadership that courts them avidly. And some Republicans who back an immigration overhaul, including Sen. Lindsey Graham, a South Carolina Republican and one of the Republican Party's most vocal champions of a pathway to citizenship, acknowledge that race remains a reality in the immigration debate.

"There will always be people [who have] different reasons for opposing the change. We have a history in this country of demagoguery when it comes [to immigration]. You know, 'Irish Need Not Apply.' There's nothing new going on today that's gone on before. This isn't the first time that there's been some ugliness around the issue of immigration," Graham said.

But Graham said despite that legacy, voters, including strong majorities of Republican primary voters, are lining up behind the idea of citizenship.

"Here's what I don't get: When you ask primary voters in a poll would support a pathway to citizenship where you have to learn English, pay a fine and go to the back of the line, it's 60% in South Carolina," Graham said. "Nationally, it's over 70% … it seems through polling, if nothing else, that the Republican Party gets it."

"There's some racist people, certainly," said Ana Navarro, a Republican strategist and advocate for immigration reform. "But I want to think it's a minority and that's not what's going to decide the immigration debate."

Graham agreed, but said he is puzzled by the resistance to moving on new immigration laws in the House.

"I don't know. I have no idea, I have no idea. I can't explain it. I think maybe it's a fear of a primary," Graham said when asked what makes his colleagues so hesitant on the issue.

With Republicans meeting in Cambridge, Md., this week to discuss, among other things, recommendations for a set of immigration policy bills, House Republicans' reluctance to touch the issue is a major facing Republicans.

"Part of it is the fact that most of our districts are more worried about a primary opponent instead of a general opponent. Immigration is a thing you get primaried over ... nobody is afraid of the pro-reform forces. They are afraid of the anti-reform forces," the operative said.

It's confusing for Republicans when in conservative states like South Carolina, Graham said, changes to immigration policy are met with much less public skepticism than perhaps many assume.

"We have a tourism economy where we need workers [and] we have an agricultural economy. I think … the employers in South Carolina make a compelling case that we need workers," Graham said.

Unlike abortion, Obamacare, the deficit, or federal spending, there's no organized, well-funded opposition: There are no media campaigns of note or lobbying blitzes on Capitol Hill. In short, Republicans feel pressure without any formal outside group really applying it.

Instead, Republican lawmakers and operatives alike also said that while fiscal issues have been driven by large, national groups like the Club for Growth and Heritage Action, Republican reluctance to tackle immigration reform is much more a bottom-up phenomenon.

Opposition to any form of citizenship for the 11 million undocumented immigrants currently living in the United States has long been an article of faith for Republican voters, much like opposition to any changes to Social Security are for Democrats. Immigration is now a third-rail issue in the GOP.

Talk radio, particularly regional and small-market talkers, have also kept up the pressure, Republicans said, explaining that the airwaves back home are constantly filled with talk of "amnesty" that makes backing new laws difficult.

Those factors, combined with the brutal beating Republicans took during the 2007 immigration reform push, means many lawmakers — even those who weren't in Congress at the time — are leery of the issue.

"I think it is an issue that left a scar. Even though opposing organizations are not as organized, are not as vocal this time around, people [still] see it [as] … a political time bomb," Navarro said.

And then there are the pragmatic Republicans in Boehner's conference, who argue turning to immigration will distract from the party's focus on Obamacare and insist sticking to that is the better political play for the party in 2014.

That argument doesn't hold much sway with advocates for new immigration laws. "I understand the desire to not distract from Obamacare. But I'm a Republican who believes we can do both. We have the momentum now," said Brian Walsh, a Republican strategist who has worked with bipartisan immigration advocacy groups.

For Walsh and other similarly minded Republicans, the greatest frustration has been what they view as the outsized influence of the small cadre of Republicans in the House, talk radio hosts and activists who they say have paralyzed the party.

Republicans are "listening to a loud minority … [but] those who oppose this haven't been challenged to say, 'What's their plan?'" Walsh said.

"They've been able to get away with yelling about part one while ignoring part two" of the political equation, he added.