Mr. Axelrod also hit Mr. Romney hard on taxes, pointing out that the United States loses $100 billion a year to offshore tax havens such as Switzerland.

“We know Gov. Romney takes advantage of these,” he said. “I’m not suggesting that he’s done anything illegal, but what I am suggesting is that he’s taking advantage of every loophole.”

“The president could do those things, but he doesn’t do those things,” Mr. Axelrod added.