Mitt gets some boos over George Romney-linked tax question

Seconds after saying he'll "probably" release more than one year's taxes, Mitt Romney was asked about his father setting a standard for releasing several years worth of returns and whether he would follow that example.

"Maybe," Romney said, smiling tightly. He got booed as he went on.

"I’ll release multiple years. I don’t know how many years," Romney said, which is what earned him boos.

He said he would not apologize for being successful, a line that then earned him cheers, and helped him close the answer strong. He said he'd earned his money himself and didn't inherit it from his parents.

But it was the second time he has struggled with the tax question in a debate in the past week.

Earlier, he said he didn't want to release his taxes "drip by drip" because it would give the Democrats something to attack on, and he would release last year's in April "and probably for other years as well."

"I obviously pay all full taxes; I'm honest in my dealings with people, people understand that," Romney said.

Newt Gingrich, who's been pressing the issue, said, "If there's anything in there that's gonna help us lose the election, then we should know it before the nomination."