Updated

Sen. Bernie Sanders, I-VT, the chamber's only self-described socialist, has lead the charge against Fed Chairman Ben Bernanke, causing considerable consternation in Washington and on Wall Street, and after a 15-minute meeting with reporters, it's clear he is not giving up without a fight.

And he says, progressives, like himself, want to see a shakeup in the President's economic team, as well.  The Vermont senator opposed the nomination of Treasury Secretary Tim Geithner earlier in the year, and when asked if this former chairman of the NY Fed (during the economic crisis) would be his next victim, Sanders implied that he wouldn’t mind if the White House made that change.

Speaking for the progressive community, Sanders called the current team "the same old same old" and said liberals have been disappointed with Obama’s personnel choices in that sector.

The feisty senator said there are "many people who want to see a new level of energy. I think the President would be very well served" to get "a populist by his side."

This is a man who goes from 0 to 90 on just about every topic about which he is passionate (and there are many), with animated, emotional floor speeches. Even with reporters in a casual "pen and pad" (ie, no cams) briefing, the temperature rose a bit, exhorting Obama to be "an FDR-type president and be prepared to take on the very powerful."

Sanders clearly admires Obama, calling him "brilliant" and "very warm and decent,” but almost to a fault. He described Obama's 2008 presidential campaign as " the best campaign I have ever seen in my life," but another thing was clear --- Sanders feels Obama has strayed from the liberal roots that got him where he is.

"He has to go back to the grassroots and say I need your help," Sanders implored.

As for Bernanke, Sanders says he will "do my very best to prevent" the chairman from getting a second term, though senior Democratic leadership aides say they are confident Bernanke will get the 60 votes needed.

Sanders said he will demand a roll call vote on both the cloture vote, that ends Sanders' filibuster which has been joined by several Republicans, and the final passage vote, but he will not require that the Senate stay in session well into Friday before final passage, as can happen under Senate procedure.