WASHINGTON -- When some senators retire, they decide to take lucrative lobbying jobs. Others go straight to Wall Street. But Wisconsin Democrat Russ Feingold, who lost his re-election bid in November, is continuing on his principled -- and often lonely -- path by starting an organization to combat corporate influence in politics, an effort he hopes will spark "a new progressive movement" that will truly hold elected officials accountable.

Launching on Wednesday, Progressives United is an attempt to to build a grassroots effort aimed at mitigating the effects of, and eventually overturning, the Supreme Court's infamous Citizens United decision that opened the floodgates to corporate spending in the U.S. electoral system. In addition to online mobilization, the political action committee (PAC) will support progressive candidates at the local, state and national levels, as well as holding the media and elected officials accountable on the group's key priorities.

"In my view -- and the view of many people -- it's one of the most lawless decisions in the history of our country," said Feingold of Citizens United in an interview with The Huffington Post. "The idea of allowing corporations to have unlimited influence on our democracy is very dangerous, obviously. That's exactly what it does ... Things were like this 100 years ago in the United States, with the huge corporate and business power of the oil companies and others. But this time it's like the Gilded Age on steroids."

Feingold said that Progressives United will follow the example of his own campaigns and not take any soft money or unlimited contributions. "We're going to be reporting every dime that we get, whether required by law or not," he insisted. "Every penny of every contribution -- a practice I used as a U.S. senator. So it will be very different from the 527s and other groups that have been spawned by Citizens United. It will be 100 percent accountable, and that is an important principle that I believe in that we'll follow to the T with Progressives United, as a way of contrasting it to what's going on with the corporate money power that's been unleashed by Citizens United."

Looking back on his time in the Senate, Feingold cited two examples of corporate influence that most troubled him: 1) the debate over the estate tax and 2) the BP disaster.

"I was amazed at the way in which the corporate powers in the country turned the conversation from everything we needed to deal with -- from stopping unwise interventions overseas to having to deal with the deficit -- to things like demanding complete repeal of the estate tax," said Feingold. "There were 10 years there we didn't have an estate tax because all of the powerful, corporate, wealthy interests in the country said, 'We want this now. We don't want to have to pay any estate tax at all.'"

He pointed to the BP oil disaster as an example of how corporate influence can permeate the executive branch, which turned the agencies who were supposed to be enforcing the laws into "tools of the oil industry," a reference to the oversight problems at the federal Minerals Management Service.

Campaign finance reform advocates have been discouraged by the new Republican majority in the U.S. House of Representatives attempting to dismantle the structure of checks that were put in place following the Watergate scandal, and have called on President Obama to take a larger role in shedding light on the issue.

White House officials originally considered having the President reiterate his support for the DISCLOSE Act during his State of the Union (SOTU) address, but it ended up getting nixed because of time constraints.

"[I]t's not for any lack of enthusiasm about the issue because we feel very, very strongly about it and we're going to continue to push for it," White House senior adviser David Axelrod told The Huffington Post. "There are a number of things that got trimmed out at the end just because, to be brutally frank, as we ran through the speech it was fairly lengthy and we just cut it down."

Feingold applauded the President for criticizing Citizens United in his 2010 SOTU speech -- prompting an unhappy response from Supreme Court Justice Samuel Alito, who was in the audience -- but he would like to see him do more on the issue.

"I would like the President to take it up a few notches on this issue, and I hope he will in the coming year and in the campaign next year," said Feingold, adding, "I'm hoping the President will recognize that what we're trying to do here is begin a new progressive movement that will hold our elected officials accountable."