Mitt Romney, Newt Gingrich Spar Over Immigration During CNN 2012 GOP Debate In Florida (VIDEO)

Earlier this week, Newt Gingrich caught criticism from Florida's Sen. Marco Rubio over an Spanish-language radio ad, in which Mitt Romney was referred to as "anti-immigrant." Said Rubio -- who is neutral in the 2012 race and has endorsed no one as of yet -- "This kind of language is more than just unfortunate. It's inaccurate, inflammatory, and doesn't belong in this campaign."

Gingrich was asked by CNN 's Wolf Blitzer during the GOP debate Thursday night to explain himself. Gingrich replied: "Why did we describe him that way? In the original conversations about deportation, the position I took, which he attacked pretty ferociously was that grandmothers and grandfathers aren't going to be successfully deported. We as a nation are not going ... to grab a grandmother and kick them out. We're not -- I think you have to be realistic in your indignation."

Of course, that's a real hair-split. Romney contends that a process called "self-deportation" will work. As Romney theorizes, if you prevent undocumented workers from obtaining a job, they'll largely leave of their own accord and attempt to re-enter legally. From there, it seems a stretch to suggest that Romney's position was the "anti-immigrant" position relative to Gingrich's, which is essentially the same, save for his preference to leave longstanding undocumented immigrants of advanced age and ties to the community alone, and extending them some residency privileges.

Blitzer correctly sensed the hair-split, and asked for clarification: "I want to make sure I understand. Is he still the most anti-immigrant candidate?"

Gingrich replied, "I think of the four of us, yes."

Romney was given the chance to intercede:

That's simply inexcusable. And Senator Marco Rubio came to my defense and said that ad was inflammatory and inappropriate. I'm not anti-immigrant. My father was born in Mexico. My wife's father was born in Wales. They came to this country. The idea that i'm anti-immigrant is repulsive.

He went on to say that Gingrich's ad was an example of "over the top rhetoric" and said he was glad Rubio "called [him] out."

Gingrich told Romney that he would give him the opportunity to "self-describe," saying, "You tell me what language you would use to describe somebody who thinks that deporting a grandmother or a grandfather from their family, just tell me the language. I'm happy for you to explain the language you would use."

Romney suggested this was beside the point: "I described following the law, which is to say, I'm not going around and rounding people up and deporting them. ... I'm not going to find grandmothers and deport them. those are your words. not my words."

Gingrich essentially continued attempting to hang the "Romney as anti-immigrant" case solely on the basis of their policy differences, where elderly immigrants are concerned. "I just want to allow the grandmother to be here legally with some rights to have residency but not citizenship so that he or she can finish their life with dignity, within the law."

Romney shot back: "You know, our problem is not 11 million grandmothers."

That the two men have a difference in their immigration policy is perfectly clear. What's not clear is why this minor difference required Gingrich to put out an ad that drew Rubio's ire. Gingrich couldn't make the case. Romney wins this round.

But Romney's "11 million grandmothers" line implied that he would let some undocumented immigrants stay put while going after the trouble-makers.

This is a see-no-evil, highly-tailored form of amnesty. And while Romney has and never will call it that, it's worth noting that he's actually practiced it in the past. As The Huffington Post's Andrea Stone reported , as governor, Romney wrote a letter to the Department of Homeland Security urging that it not deport a beloved teacher from his state who was in the country illegally.

As Romney told CNN at the time, he appreciated the need to apply the same rules to everybody. "But now and then," he said, "when a group of kids come together and say this is different. Please all you people at the top of the pyramid of the public service world, will you stop and look at this? This is different. It doesn't fit the rule."

Romney wrote a letter to Homeland Security Secretary Michael Che rtoff -- now an adviser to his presidential campaign -- saying, ''I have heard from scores of Mr. Attouoman's students who are concerned that the loss of their teacher in the middle of this school year will not only impact their education, but also will take from our community a man who has been willing to mentor young men who lack a prominent role model in their lives."