Obama campaign: Don't blame us for ad blaming Romney for cancer death

— -- President Barack Obama's reelection campaign distanced itself on Wednesday from a harsh—and misleading—ad that effectively ties Mitt Romney's business decisions to a woman's cancer death. But neither the campaign nor the White House passed judgment on the vicious commercial, which emerged from a super PAC backing Obama.

"We have nothing, no involvement, with any ads that are done by Priorities USA. We don't' have any knowledge of the story of the family," Obama campaign spokeswoman Jen Psaki told reporters aboard Air Force One.

"As you know, campaign finance rules in that regard are in place for a reason," she said, referring to laws forbidding outside groups from coordinating with the presidential campaigns.

White House press secretary Jay Carney, who ducked questions about the ad on Tuesday but invited reporters to "ask me tomorrow," declined to discuss it.

"I haven't seen the ad, but I have read about it. And I speak for the president, I do not speak for a third party organization," Carney said in the same briefing.

Both Carney and Psaki sought to turn the discussion to Romney's misleading attacks on Obama's welfare policy.