President Obama says he won't apologize to Mitt Romney

"He's very willing to take credit for everything good that he thinks happened after that point that Bain Capital was involved in, but he's not willing to take responsibility for this," Obama strategist David Axelrod said, echoing comments Obama and his allies leveled in a weeklong blitz about Bain.

Sen. Kelly Ayotte, R-N.H., said Obama's attacks cheapen the presidency and are an attempt to distract voters from Obama's record in office.

"With these attacks, it shows that he's just a small politician and running on small-ball politics at a time when our country is facing grave, grave challenges," Ayotte said.

Added Gillespie: "We now know this president will say or do anything to keep the highest office in the land — even if it means demeaning the highest office in the land."

Romney's campaign released a television ad Sunday asking why the president had stopped talking about hope and change, his signature message during the 2008 campaign, and criticizing him for a barrage of negative ads against Romney.

Obama's allies also pushed Romney to release more than the one year of tax returns he has shared. Chicago Mayor Rahm Emanuel, Obama's former top White House aide, noted Romney released 23 years of taxes to 2008 GOP nominee John McCain so he could be considered as a vice presidential nominee.

"John McCain's people looked at it and went with Sarah Palin" as the No. 2 on the ticket that year. "Whatever is in there is far worse than the first year," Emanuel said. "The Romney campaign isn't stupid. They have decided that it's better to get attacked on a lack of transparency, lack of accountability to the American people, versus telling you what's in those taxes."

Romney has refused and says that no amount of disclosure would satisfy his critics.

But some in his party said the debate over Romney's wealth is distracting from the campaign.

"He should release the tax returns tomorrow. It's crazy. You've got to release six, eight, 10 years of back tax returns," said conservative Bill Kristol, joining the Republicans who want to turn the page on stories about Romney's vast personal wealth. "Take the hit for a day or two."

Unless, as Obama's team hints, the returns prove disqualifying.

"The costs of not releasing the returns are clear," conservative columnist George Will said. "Therefore, he must have calculated there are higher costs to releasing them."

Gillespie appeared on NBC's "Meet the Press" and CNN's "State of the Union. Cutter and Madden were on CBS' "Face the Nation." Axelrod spoke to CNN. Kristol was interviewed on "Fox News Sunday." Emanuel, Ayotte and Will appeared on ABC's "This Week."

Associated Press writer Michele Salcedo in Washington contributed to this report.