Priorities USA Action, a group run by former aides to President Barack Obama, is spending $100,000 to run advertising across social media websites such as Facebook, Google, YouTube and news websites.
A Web video released by the group labels Romney as the Republican front-runner and outlines the policies it says the nation could expect if Romney wins the White House next year.
The video opens with Republican strategist Karl Rove saying Obama will not be able to win re-election and includes clips of Romney saying "corporations are people" and the housing foreclosure process needs to "hit the bottom."
