Former Sen. Russ Feingold (D-Wis.) launched the Progressives United political action committee this week in response to the Citizens United Supreme Court decision and to support progressive candidates.

Feingold announced the formation of the PAC just more than a year after the high court struck down limits on corporate political ads. Progressives United aims to mobilize grass-roots support for overturning the Citizens United v. Federal Election Commission decision, according to the organization’s website.

“After the Supreme Court’s egregious Citizens United decision last year, which opened the floodgates for corporations to influence our elections, we saw hundreds of millions of dollars from corporate special interests drown out the voices of average Americans and obstruct the democratic principles established by our nation’s Founders,” Feingold wrote in a blog dated Tuesday on Progressives United’s website. “That flood of corporate money began to make an impact in last fall’s election. But our real fight is ahead, when special interests will try to buy their way to victory in 2012.”

The PAC will support progressive candidates in national, state and local elections.

Feingold and Blanche Lincoln of Arkansas were the only two Democratic Senators unseated in the Nov. 2 midterm elections. He had initially been viewed as a safe bet for re-election but lost to Republican Ron Johnson.

The Wisconsin Democrat has also joined Marquette University Law School in Milwaukee as a visiting professor for the spring semester.