“I’m really encouraged by what I’m seeing. People around the country are finally organizing to stand up to the huge influence of corporations on government and our lives. This kind of citizen reaction to corporate power and corporate greed is long overdue.”

That’s Russ Feingold, who spoke with me yesterday in order to voice his strong support for Occupy Wall Street, making him one of the most prominent liberal Democrats in the country to endorse the protests. Feingold’s strong backing will be seen as significant by the movment’s supporters, because thus far few elected Dems have publicly voiced support for it.

Feingold’s career has been all about fighting the influence of corporate money over politics — he championed campaign finance reform, opposed deregulation and voted against Obama’s Wall Street reform bill because it didn’t go far enough — so he has an interesting perspective on the budding movement.

Feingold rejected the argument — made even by some of Occupy Wall Street’s sympathizers — that it has failed to articulate a clear message or agenda, arguing that the coalescing of outrage itself is the story and the message here, even if it seems incohate at times.

“The guys who are protesting are not filing legal briefs,” he said. “They are expressing the populist, genuine view that people have been ripped off. It’s a fundamental identification of the fact that people are getting taken for a ride by powerful interests who are getting away with murder.”

“The worm is finally turning on the nonsense of blaming the wrong people for what happened in 2008,” said Feingold, whose new group, Progressives United, was formed to counter the Citizens United decision and corporate influence over politics. “The American people are saying, wait, we have the boot of corporations on our necks, and we’re sick of it. This is a significantly coherent message at the beginning of something like this.”

Feingold said he was moved to speak out because of condescending media coverage of the issue, adding that it’s crucial to understand that Occupy Wall Street is rooted in the emotional reality of people’s everyday experiences of the economy.

“This is a populist movement based on genuine suffering and fear,” he said. “Anyone who really lives out in working America knows that people are feeling very scared. This movement would probably not have this fuel if not for that reality.”

Asked whether the Obama administration and the Democratic Party’s insufficiently confrontational approach towards Wall Street is partly to blame for all the frustration, Feingold noted that there are still signficant differences between the two parties. But he offered Obama some advice.

“The White House should realize that this would be beneficial to the president and his reelection chances if he recognizes how correct the protesters are to be upset,” Feingold said. “It would be a mistake to try to coopt this. I’m hoping a mass movement will encourage the White House to listen to and respond to these concerns. It would be politically smart and the right thing to do.”

“This is like the Tea Party — only it’s real,” Feingold said. “By the time this is over, it will make the Tea Party look like ... a tea party.”