...so very, very sorry that he accepted the consensus scientific position on climate change and responded by endorsing a market-friendly policy response that has worked in the past:

The moderator announced that everyone should turn their attention to a old radio ad for an environmental group in which Mr. Pawlenty heartily endorses a cap-and-trade policy — practically apostasy in his party.
“Do we have to?” Mr. Pawlenty quipped awkwardly. His voice soon echoed through the auditorium saying “cap greenhouse gas pollution now!”
But in a response that was clearly carefully prepared, Mr. Pawlenty looked right at the camera after the radio ad played, apologized to the American people, and said he had made a “mistake.”
“I’ve said I was wrong. It was a mistake, and I’m sorry,” Mr. Pawlenty told the Fox television audience, presumably filled with potential Republican primary voters. “You’re going to have a few clunkers in your record, and we all do, and that’s one of mine. I just admit it. I don’t try to duck it, bob it, weave it, try to explain it away. I’m just telling you, I made a mistake.”

Pawlenty is trying to turn the very abjectness of his reversal into a kind of character testimonial. He chopped down the cherry tree. He's facing up to his error and he won't repeat it.

Of course this formulation allows Pawlenty to explain why he made this "mistake." The real reason, of course, is that cap-and-trade was considered an acceptable thing for Republicans to believe four years ago, but the party has turned sharply rightward, so he is abandoning his no-longer-acceptable position in order to win the GOP nomination. If cap and trade remained popular among Republicans, but they had decided that, I don't know, food safety inspections represented the greatest threat to freedom in world history, he'd be standing behind cap and trade and apologizing profusely for his previous support for the F.D.A.

Pawlenty can't say that, obviously. So he substitutes stridency for explanation. But it would be interesting to see some reporters try to put pressure on Pawlenty's apology. What exactly did he get wrong? Does he believe that energy producers should be allowed to dump carbon into the atmosphere at no cost whatsoever in perpetuity? That line of inquiry could be illuminating, and probably fun.