Restore Our Future, a super-PAC backing Mitt Romney, has purchased $1 million in radio airtime to attack President Obama's record on the economy.

"Imagine you were Barack Obama. What would you do now? You spent a trillion taxpayer dollars on the stimulus. It failed," the ad's narrator says. "The jobless rate went up and has been stuck above 8 percent for 41 straight months. You increased spending so wildly that you've added more debt than the first 41 presidents — combined."

The ad then quotes Bill Clinton referring to Romney's "sterling business career" and says Democrats and the media derided Obama's attacks on Romney as "blowing smoke, go[ing] too far and [being] supported by no evidence."

"With no record to run on, it's the only strategy that Obama has left," the ad closes.

The salvo is the latest in the back-and-forth between Obama pushing to define Romney as a heartless outsourcer and Romney blasting Obama as a failed president on the economy. It will run in most of the major swing states, including Colorado, where both campaigns had pulled their attack ads off the air in the wake of the Aurora shootings.

Listen to the ad: