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BOSTON - An ad developed by a pro-Obama SuperPAC that suggests Mitt Romney is responsible for a woman's death has hurt President Obama's credibility and "squandered" the president's best attributes, a senior adviser to Mitt Romney's campaign said today.

"They're accusing the governor of being a felon. They are accusing him of culpability in the death of a woman," said Eric Fehrnstrom during a briefing with reporters at the campaign's Boston headquarters. "These attacks are so outrageous and over the top that it has squandered one of the most vital attributes that Obama had, which is he was a different kind of politician who was going to change the state of our politics. And as I've said he has changed it, but he's changed it for the worse."

Romney's campaign released a new television ad today, "America Deserves Better," that echoes Fehrnstrom's comments and asks the question, "Doesn't America deserve better than a president who will say or do anything to stay in power?"

The campaign was referring primarily to a Priorities USA Action ad the group plans to air later this week in which Joe Soptic, a former GST Steel worker, explains how he lost his job and health benefits when Romney's Bain Capital closed his plant. Soptic's wife later became ill and died shortly after she was diagnosed with cancer. "I do not think Mitt Romney realizes what he's done to anyone, and furthermore, I do not think Mitt Romney is concerned," Soptic says in the ad.

The Obama campaign, which had initially claimed they had no knowledge of Soptic, said Thursday that they had in fact worked with him before.

"I think when you start running ads accusing your opponent of killing people, then you have lost credibility and I think that's where the Obama campaign finds itself," said Fehrnstrom.

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Previous ads aired by the Obama administration had suggested that Romney had dodged paying taxes, a felony.

"This is a case where the Obama campaign has engaged in, not only in outright falsehood by accusing Mitt Romney of responsibility with the death of a woman, but beyond that their campaign has deceived the public over what they knew about it," said Fehrnstrom.

The Romney campaign has also been accused of an ad that contains inaccurate statements when it claims that the Obama administration is trying to remove all work requirements from the welfare system.

Pressed on how important it is for the Romney campaign to run ads that are factually accurate, Fehrnstrom responded, "That's a question that should be put to President Obama and his campaign team. Are they committed to accuracy?"

"Of course it's important that candidates not engage in wild exaggerations and distortions of truth, which is what we've seen from the Obama campaign," said Fehrnstrom.

A spokeswoman for Obama's reelection campaign dubbed Fehrnstrom's comments to be "faux outrage" that "rings extremely hollow."

"Mitt Romney won the Republican primary only by tearing down each of his opponents with ruthlessly negative campaigning, including ads funded by outside allies. His campaign has questioned whether the president understands what it is to be American, attacked his patriotism, and is currently running an ad that a former president and authors of the welfare-to-work legislation have called a flat-out lie. When the Romney campaign finally reaches the high ground, we look forward to greeting them there," said spokeswoman Lis Smith.

ABC News' Mary Bruce contributed to this report