American Crossroads, the super PAC advised by former Bush administration strategist Karl Rove, is going on the air with a $9.3 million campaign attacking President Obama for his negative campaign against former Massachusetts governor Mitt Romney.

“What happened to Barack Obama?” a female narrator asks. “The press and even Democrats say his attacks on Mitt Romney’s business record are misleading, unfair and untrue.” The president is going negative, she says, because of high debt and unemployment — “Obama can’t run on that record.”

Romney has repeatedly called attention to Obama’s negativity, airing his own ads suggesting the president is a hypocrite and a liar.

Conventional wisdom has it that responding to negative campaigning is a waste of time. Voters say they don’t like negative ads, but in the end, they don’t vote on that dislike. Byron York, a conservative columnist at the Washington Examiner, suggested Romney was “whining” by complaining about the ads, which focus on the former Massachusetts governor’s career at Bain Capital.

But clearly, both Romney and his allies think there’s something to be gained by hammering on Obama’s Bain Capital attacks, which may be having an effect in swing states.

The Crossroads ad will air in Colorado, Florida, Iowa, Michigan, North Carolina, New Hampshire, Nevada, Ohio and Virginia.