“Instead of balancing the budget on the backs of working families, the elderly, the children, the sick and the most vulnerable,” Sanders said, “it is time to ask the wealthiest people and most profitable corporations in this country to pay their fair share.”

In several speeches to crowds numbering in the thousands who gathered for Fighting Bob Fest events in Madison Friday and Saturday, Sanders spelled out the progressive economic agenda — opposition to cuts in Social Security, Medicare and Medicaid to balance budgets and address deficits, and support for tax policies that end special breaks for the wealthy and multinational corporations that offshore jobs from the United States.

Sanders credited the Obama White House’s decision to reject “changes to Social Security” as part of a deficit reduction strategy.

“I am delighted that the White House has decided not to cut benefits under the program that has kept millions of retirees out of poverty,” the senator said in Madison. “Social Security has a $2.5 trillion surplus, can pay out every benefit for the next 27 years and has not contributed one nickel to the deficit. Social Security should be strengthened, not cut.”

But just because Obama got Social Security right does not mean the House-Senate supercommittee on deficit reduction — which is ramping up its work — will do so. Nor does it mean that related and equally vital programs, such as Medicaid and Medicare, are off the chopping block.

Sanders has taken the lead in the fight against balancing budgets on the backs of working Americans,

He’s pushing a number of plans designed to strengthen the safety net, while demanding that the richest Americans — who have enjoyed massive increases in their income and wealth in recent years — begin to pay their fair share.

Some of the loudest applause for Sanders at Bob Fest — the annual series of events named for Wisconsin progressive-populist Robert M. La Follette — came when he outlined a plan to ensure the long-term stability of Social Security. Princeton professor Cornel West, Congresswoman Tammy Baldwin, radio host Thom Hartmann and others also addressed an arena filled with labor, farm and community activists for Saturday’s main Bob Fest gathering.

Currently the Social Security tax is capped so that people do not pay it on annual income over $106,800. Arguing that the most effective way to strengthen Social Security for the next 75 years is to raise the cap to $250,000, Sanders declared: “Lift the cap and cause the wealthiest Americans to pay their fair share.”

Thousands of activists whose level of commitment will decide the fate of Democratic contenders in 2012 leapt to their feet and cheered.

If President Obama and other Democrats in Washington want to know how to leap the enthusiasm gap that will be needed to win battleground states such as Wisconsin, Iowa, Ohio and Pennsylvania next year, Sanders has provided the answer.

Asked at a packed Friday night gathering in Madison to explain how Obama and the Democrats can win next year, the senator answered: “Clearly, you are not going to win over the American people unless you are prepared to stand and fight.”

Again, the applause was thunderous.

Let’s just hope it was loud enough to be heard in Washington by the president and by the Democrats who have been assigned to the supercommittee.

John Nichols is the associate editor of The Capital Times. jnichols@madison.com