© Matthew J. Lee/Globe Staff Presidential candidate Bernie Sanders spoke at a rally at the MassMutual Center.

SPRINGFIELD — Buoyed by his front-runner status, US Senator Bernie Sanders brought his populist, progressive message Friday to a big, raucous crowd that cheered wildly throughout his pledges to champion the working class.

“This is just not a campaign,” Sanders said to nearly 5,000 people at the MassMutual Center. “This is a movement that says to the corporate elite, you cannot have it all. We’re coming back.”

The crowd responded with chants of “Bernie! Bernie!” as he told them the political and corporate elites are “getting nervous” about the early success of his primary campaign.

“They have a right to get nervous. We’re going after them,” Sanders said to roars of approval. “Whether the corporate elite likes it or not, we intend to create a government that works for us, not just a few."

Sanders trumpeted his familiar proposals for universal health care, free college tuition, affordable child care, nationwide legalization of marijuana, and aggressive action on climate change.

“We are standing together for an agenda that works for all of us,” Sanders said to loud applause. “Don’t listen to Congress’s or the media’s definition of reality,” he added. “Ask yourself where should this country be going.”

Sanders urged the young to get involved in shaping government.

“Many of your friends think that politics is [expletive], right?” Sanders asked to laughter. “Stop complaining! Tell them to get involved in the political process.”

In the end, he said, “we are united together to be sure we defeat Donald Trump, the worst president in the modern history of America.”

“We’re going to beat Trump, and we’re going to beat him badly," he added. “We are in the process of putting together an unprecedented, multiracial, multigenerational, grassroots movement.”

Before the speech, a snaking line of supporters and the curious wrapped around the MassMutual Center two hours before Sanders brought his formidable presidential campaign here, four days before the Super Tuesday primaries.

There were seniors, there was a Potsquatch character advocating for marijuana, and there were the young. Throngs of them. Dressed in jeans, and woolen caps, and plaid jackets, waiting for a chance to hear a 78-year-old they say speaks their language.

“I like his ideals. I like his passion. And I like his idea of helping each other and spreading the wealth,” said Arius Johnson, 23, who made the short trip from Hartford to hear Sanders. “And I don’t think he’s too left to beat Trump. There are enough people in the middle that can be swayed his way.”

If the rally held a retro, quasi-Woodstock feeling, that seemed intentional. Banjo player Bela Fleck played “This Land Is Your Land” for the cheering crowd, and followed that Woody Guthrie standard with the national anthem strummed in a minor key.

“It’s kind of a complicated time in America, don’t you think?” Fleck asked the crowd.

It’s also a complicated time in the Democratic primary campaign, with Sanders using a rousing message to energize his base and attempt to stave off his progressive rival, US Senator Elizabeth Warren of Massachusetts, and a gaggle of moderates who say Sanders is too radical to defeat President Trump in November.

Former vice president Joe Biden is expected to win the South Carolina primary Saturday, but Sanders had managed to chip away at what had been a formidable gap. It was a sign of his focus on Super Tuesday, when Massachusetts will vote, that Sanders visited Springfield the night before the first primary election in the South.

Sanders is scheduled to lead a rally on Boston Common on Saturday.

His supporters hailed Sanders’s support for Medicare for All, his calls for free college tuition and the eradication of student debt, and his withering criticism of what he calls the unequal distribution of wealth in the United States.

"I like the consistency of his message for decades and decades now, and the fact that he cares about regular people,” said Nicole Berndt, 35, of Granville.

Her husband, Adrian, 31, said he doesn’t think Sanders is too far left to defeat Trump.

“He’ll try to go after the big companies to pay their fair share,” said Berndt, a construction worker who added he does not believe the senator’s sweeping social proposals will take money from the middle and working classes, too.

Shanice Smith, 26, of Westfield, held a blue “Bernie” sign, but said she had not decided who will get her vote Tuesday.

“You’re never too sure, right? Someone can throw you a curveball. I’m looking for a sense of overall consciousness," said Smith, a mother who works with the disabled. “He seems cool. He’s made his money but not the con-man way.”

State Representative Paul Mark, who represents part of Western Massachusetts, whipped up the crowd before Sanders’s speech, calling the candidate a consistent and passionate progressive.