Maryland Gov. Martin O’Malley (D) and Virginia Gov. Robert F. McDonnell (R) sparred over Mitt Romney’s tax returns, Medicare and the tone of the presidential campaign on NBC’s “Meet the Press” Sunday morning.

Virginia Gov. Robert F. McDonnell (R) (Steve Helber/AP)

“I know when reviewing tax returns of vice presidential hopefuls like Governor McDonnell or, indeed, Paul Ryan, he asked for more than one year of tax returns,” O’Malley said.

Maryland Gov. Martin O'Malley (D). (Patrick Semansky/AP)

“We know that he has been engaged in tax-avoidance schemes with offshore accounts in the Cayman Islands and the Bahamas,” O’Malley said. “It’s not unlawful, but it is tax avoidance. At a time when our country needs everyone’s help to accelerate our nation’s recovery, he’s hiding his money in offshore accounts and betting against the future of the United States.”

McDonnell shot back: “That’s just flat wrong, Martin. This is the same reckless and slanderous remarks that [Senate Majority Leader] Harry Reid (D) said a couple of weeks ago. This isn’t what the American people care about. This is below their dignity. This is about how do we get the greatest country on earth out of debt and back to work. And Obama just flat failed. Nice guy, bad policies. Hasn’t gotten the job done.”

Both governors, who lead rival, partisan governors associations, accused the other side of resorting to incendiary, untruthful attacks.

McDonnell took issue with comments Vice President Biden made in Danville last week. Biden told the crowd there that Romney’s plan to “unchain Wall Street” would “put y’all back in chains.” McDonnell said he agreed with the nation’s first elected black governor, Doug Wilder of Virginia, that the remark had injected race into the campaign.

“Incendiary and way over the top,” is how McDonnell described it.

O’Malley called the comments “an indelicate choice of words,” but added, “There’s not a racist bone in Joe Biden’s body.”

O’Malley said Republicans were the ones bringing race into the campaign, by falsely accusing Obama of “unwinding welfare reform.” He noted that McDonnell has personally pushed that line of attack.

“Governor Romney himself has launched a series of attack ads falsely accusing the president of unwinding welfare reform,” O’Malley said..”It’s been determined false. Governor McDonnell himself was labeled as false by his own PolitiFact in Virginia for saying that the president’s trying to do that.”

McDonnell did not respond directly o those comments.

On the subject of Medicare, Gregory noted that Ryan has said that Obama’s health-care overhaul had robbed Medicare of $716 billion.

“Ryan made those same cuts in his own budget,” Gregory said to McDonnell. “Don’t you think that criticism is over the top by the Republican ticket?”

There was a pause, as McDonnell, in a remote studio, waited to hear the whole question. O’Malley, who was on the set with Gregory, jumped in with a cheerful: “I do!”

McDonnell then offered his take: “We’re broke and they’re being honest about the fact that we’re broke.”