Atlanta --

Newt Gingrich has charged into the fray over illegal immigration, risking conservative ire just as his Republican presidential campaign - once declared all but dead - has vaulted into front-runner status.

The firebrand former House speaker broke with what has become a reflexive Republican hard line on immigration, calling for "humane" treatment for otherwise law-abiding illegal immigrants who have been in the United States for decades, establishing deep family and community ties.

Gingrich suggested they should be provided a pathway to legal residency but not citizenship. Republicans, he said, should see illegal immigrants through the prism of another issue near and dear to the GOP faithful: family values.

"I don't see how the party that says it's the party of the family is going to adopt an immigration policy which destroys families that have been here a quarter century," Gingrich said at a televised debate Tuesday night.

'Significant harm'

The response was swift, and some conservatives asserted he had wounded his candidacy, perhaps fatally.

"Newt did himself significant harm tonight on immigration among caucus and primary voters," tweeted Tim Albrecht, deputy chief of staff to Iowa Gov. Terry Branstad, whose state holds the leadoff caucuses in January.

Immigration has proved to be politically treacherous for Republicans trying to appeal to the party's conservative base. Just ask Texas Gov. Rick Perry, who said critics of in-state tuition for illegal immigrants "did not have a heart." Perry had to apologize for the remark.

But others praised Gingrich for emerging as a "voice of reason" on an emotionally charged topic.

"With me, personally, I fall right in line with him," said Columbia, S.C., Gingrich supporter Allen Olson, a former Tea Party official. "It's utterly impossible to round up 12 million people and ship them off."

Consistent stance

The stance is not a new one for Gingrich. Aides say he was saying the same thing at town halls and forums long before he was running for president. It's laid out on a campaign Web page.

What is new is the scrutiny he's receiving. Recent polls have shown Gingrich at or near the top of the Republican field, along with Mitt Romney. With a little less than six weeks to go until the Iowa caucuses, people are listening to the former Georgia congressman.

And far from a stumble, Tuesday night's remarks seemed a calculated tactic to draw a contrast with Romney, whom he now sees as his chief rival to the party nomination and who has had his own trouble with conservatives, largely because of the health care overhaul law he pushed through as governor of Massachusetts.

But Romney has been tough on illegal immigration while running for president. He said Tuesday night that what Gingrich was proposing would act as a magnet for foreigners to enter the country illegally.

The Gingrich team countered by pointing to comments Romney made on NBC's "Meet the Press" in 2007, during which he called proposals similar to the one Gingrich was backing "reasonable."

While in Congress, Gingrich voted for amnesty for illegal immigrants in 1986 and for smaller, more specific amnesties throughout the 1990s, said Roy Beck, president of NumbersUSA, which advocates tighter immigration controls. The organization gave Gingrich a "D" for his time in Congress.