There was a moment, toward the end of the CNN debate, when Newt Gingrich took over with what he knows is an unpopular position in a Republican primary.

Sounding suspiciously like a compassionate conservative, Gingrich said that if you’re an illegal immigrant who has lived here for 25 years and obeyed the law and is part of the community, “I don’t think we’re going to separate you from your family…and kick you out.”

Mitt Romney strongly challenged the former House speaker, saying that approach sounded like amnesty and would only serve as a “magnet” for illegal migration from Mexico. But Gingrich stood his ground. “Let’s be humane,” he said.

In crass political terms, Romney may have gained more by embracing the anti-immigration stance. But Gingrich showed he was willing to fight for a principle, and he did it without attacking anyone on the stage. He may get beaten up for it, as Rick Perry was when he defended tuition breaks for children of illegal immigrants, but he resisted the urge to pander.

It was a wonky foreign-policy debate overall, but Romney and Gingrich managed to beat the Blitz.

They did it in very different ways in fielding questions from moderator Wolf Blitzer, whose name Herman Cain comically mangled. Romney showed an unusual degree of passion in defending the war in Afghanistan and opposing Pentagon budget cuts, while Gingrich lectured Blitzer and the audience on what America would do “if we were a serious country”—making sweeping pronouncements with more than a touch of condescension.

They were the winners Tuesday night, although the face-off in Washington, cosponsored by the Heritage Foundation and American Enterprise Institute, won’t move the needle much in a campaign dominated by the economy. Cain faded with vague answers; asked if the U.S. should continue international spending on AIDS, he said, “It depends on priorities.” As does every issue at the White House.

Perry talked tough—with not a single brain freeze—but some of his pronouncements seemed like debating points. Impose a no-fly zone on Syria! Leon Panetta should resign over defense cuts! Oh, and Ron Paul got an awful lot of airtime.

Most of them talked tough on Iran, but if it was easy to stop Ahmadinejad’s nuclear program, previous presidents would have done it.

Gingrich has revived his dormant campaign by using these debates to showcase his ideas. And he has a lot of them. But are Americans going to want a privatized Social Security system à la Chile, as Gingrich pitched on Tuesday night?

Still, this topsy-turvy contest may finally be heading toward a two-man race—unless Gingrich’s risky immigration stance erodes his frontrunner status.