Romney may not be ideal on immigration, but he was better than McCain or Giuliani in the New Hampshire debate—Joe Klein writes in Time Magazine's "Swampland" blog:

And then, in the emotional heart of the debate—the illegal immigration section—Mitt Romney, loathsome as always on this issue, had both McCain and Giuliani totally on the defensive about the definition of amnesty. Romney's argument that a $500 fine wasn't amnesty is ridiculous. What sort of hoops does he want the illegals to jump? Does he want all 12 million in prison? Does he want to deport them—and, if so, how? (Hillary Clinton had an extensive answer on the number of buses and law enforcement officials—tens of thousands—who would be needed to get the job done at one of her rallies today.)

McCain's Lost Weekend - Swampland - TIME

Klein has it backwards—Romney's argument was that McCains's plan to let illegals pay $5,000 (not $500) was equivalent to amnesty.

MR. ROMNEY: No, no, no, no. I get a chance to respond to this. I'm sorry. I'm sorry.

I don't describe your plan as amnesty in my ad. I don't call it amnesty. What I say is — and you just described what most people would say is a form of amnesty. Yeah, they pay $5,000, their background is checked, they have to learn English. But your view is everybody who's come here illegally, today, other than criminals, would be allowed when they speak English and get $5,000 payment and they get a background check, they're allowed to stay forever.

SEN. MCCAIN: Look —

MR. ROMNEY: That's your plan, and that plan, in my view, is not appropriate. Those people should be invited to get in line outside the country with everybody else who wants to come here. But they should not be given a special right to stay here[Debate Transcript]

Furthermore, Joe Klein doesn't seem to be happy with the Republican at a focus group he attended:

I"m not sure this was a representative group of Republicans. They seemed pretty conservative. And they...Just. Loved. Romney. Most of those who came in undecided had switched to Mitt by the end of the show. They just adored his position on illegal immigration (their dials plummeted when McCain said we had to be "humane.")

Let me explain what "humane" means in liberal-speak—it means letting people get away with murder. McCain really doesn't care about the victims of illegal immigration, any more than the ACLU cares about the victims of crime. He wants to be humane to the illegals. That's why the dials plummeted, not because Republicans are inhumane, but because they don't like betrayal, and that's what they can expect from Humane McCain.