"It made me sick to bail out the banks, but I had to clean up the mess left by these guys," Sestak adds, with a photo of Toomey and Bush behind him.
Toomey complained Monday that Sestak, a U.S. representative, is using the ad to duck responsibility for his votes on such things as the Wall Street bailout and the economic stimulus package.
"The fact is, Joe Sestak deserves more than his fair share of the blame for this, and nobody but Joe Sestak is responsible for his votes," Toomey said. "I just don't think people are going to be fooled by that."
Every election appears to feature at least one memorable ad that manages to break through the heavy clutter of campaign attack commercials that flood the television airwaves. Pennsylvania Democrats are hoping Sestak's dog ad can propel him to the Senate.
Donald Bradbury, 43, an independent from the Philadelphia suburb of Media who is leaning toward voting for Toomey, said he snickered when he first saw the ad. But he'd prefer it if candidates ignored gimmicks and stuck to the issues.