Pro-Obama ad rips Romney's '47 percent' remark

The ad opens with a shot of a mansion. "Behind these doors Mitt Romney calls half the American people 'dependent upon government, who believe they are victims,' " the ad says, using words captured at a private Romney fundraiser and widely circulated this week against him before cutting to a shot of a middle-class home. "Victims? Behind these doors middle-class families struggle. And Romney will make things even tougher, raising taxes by up to $2,000 to give multimillionaires a $250,000 tax break."

The ad then jumps back to the Romney fundraising video, with the candidate saying, "I'll never convince them they should take personal responsibility," before concluding, "And Mitt Romney will never convince us he's on our side" as "If Mitt Romney wins, the middle class loses" appears on the screen.

The ad is the first from Democrats to make hay out of the comment, which has dominated the headlines this week and even some Republicans warn could deal a body blow to Romney's struggling campaign.

Romney has spent more than a day on defense over the remark, standing by its meaning while apologizing for the way he phrased it. He has argued that he meant the 47 percent of voters who will always vote Democratic, not the 47 percent who don't pay income taxes, which includes many GOP-leaning constituencies, including seniors and active-duty military personnel.