In an interview with journalist Bill Moyers that will air Friday, U.S. Senator Bernie Sanders (I-Vt.)—who has announced he is seriously considering a run for president in 2016—said that though voter turnout is key in order to keep Republicans and their regressive polices from making gains in Congress and local elections nationwide, the real challenge for progressives in the coming days, months, and years is to build a powerful grassroots movement that is able to break the stranglehold that big money and corporate interests have placed on the nation's democratic insitutions.

"What we have got to do is mobilize the American people in a way that we have not seen in recent history around a progressive agenda," said Sanders.

When asked by Moyers how such a mobilization might be realized, Sanders admitted that he does "not have any magical solutions," but said that when people begin to stand up and say "Enough is enough"—and talk about doing well by their kids, protecting the environment, fighting corporate interests, winning healthcare for all, and taking on the billionaire class—the movement from below will inevitably shift the current debate. "When people begin to move, the people on top will follow them," he said.

"What I do know," Sanders continued, is that the landscape of U.S. politics will not change for the better "if we do not create an economy that works for ordinary people, if we do not end the fact that 95 percent of all new income now goes to the top one percent. We've got to end it, and the only way I know to do that is to rally ordinary people around the progressive agenda. So our job is to create a 50 state, grassroots movement around a progressive agenda."

Asked by Moyers about similar-sounding populist rhetoric used by President Obama when he first ran for president in 2008, Sanders responded: "I have lot of respect for Barack Obama. But, his biggest mistake is that, after running a brilliant campaign in 2008, where millions of people in fact were galvanized, young people, people of color came out and said, 'Hey, we're going to make some real change.' The day after the election he said, okay, thank you very much. Now I'm going to work inside the Beltway and we're going to start negotiating with Republicans and all that stuff. The simple truth is, in my view, nothing gets done unless millions and millions of people will demand it. Politics is 365 days a year."

"Not just voting?" asked Moyers.

"Exactly," said Sanders. "And anyone, you can have the best person in the world as president of the United States, that person will accomplish nothing unless millions of people are standing behind him or her."

Watch the full interview: