Former House Speaker Newt Gingrich threw down the gauntlet to conservative Republicans at Tuesday night's presidential debate, challenging his rivals to upend his argument against mass deportations of illegal immigrants while also taking a huge risk with the law-and-order GOP base.

The Republican presidential hopeful, who has sprung to the top of the polling charts in the past two weeks, warned against a policy that proposes deporting illegals who have been in the country for 25 years. Gingrich said he would not "expel" those who have come to the United States illegally if it happened decades ago.

And in an appeal to family values, he said long-residing illegal aliens shouldn't become citizens, but neither should they be torn apart from their families.

"I don't see how the party that says it's the party of family is going to adopt an immigration policy which destroys families which have been here a quarter century and I'm prepared to take the heat for saying let's be humane in enforcing the law," he said.

Heat is what he got.

Rep. Michele Bachmann and former Massachusetts Gov. Mitt Romney both pounced on the suggestion, calling it a form of amnesty that attracts illegal immigration. Romney added that he wants to encourage immigration, especially among those educated at U.S. colleges...