CEDAR RAPIDS, Iowa — A local band belts out a cover of “Rockin’ in the Free World,” warming up the crowd for speakers who will rail against the rich while, fittingly, a mustachioed young man with wire-rimmed glasses sits on the concrete floor in the back of the venue, silently poring over a well-worn paperback of “A People's History of the United States.”

More than 3,000 people have crowded into the U.S. Cellular Center in the second largest city in the state to hear from Bernie Sanders and to listen to the Grammy Award-winning indie band Vampire Weekend. It is the biggest Iowa crowd to date for the candidate, and some in the audience tease one another about whether they’re here for a free concert or for a political revolution.

Most are young. Sanders needs them all to win the caucuses Monday night in this first state to vote in the 2020 primary.

Polling shows that the young are predisposed to support Sanders, and more polling shows that the young are inoculated against the ideological attack most often used to dismiss him.

Rep. Ilhan Omar warned another crowd, that one at nearby Simpson College earlier in the day, that this kind of critique was coming: As Sanders rise in the polls, they will see more attacks. “You might even hear the ‘S-word’—socialism,” the Minnesota Democrat said. “But make no mistake these are the same attacks the status quo has used throughout history to demonize multi-racial, working-class movements.”

Omar need not have worried. At least, not about the Cedar Rapids crowd.

“I am big into socialism,” says Kate Hughes. A college student, she learned in class that the rich were once taxed at nearly 70%. And, she asks, wasn’t Franklin Roosevelt a socialist? He was one of the best presidents in her estimation, and the young fan believes “we need more taxes to fund programs that are necessary for a thriving economy.”

“Bernie knows we live in a capitalist society, and him being president is not going to change that, but it is going to provide more of a socialist lens,” Hughes explains before admitting that the higher taxes that Sanders proposes “aren’t going to change much for me.”

Sanders would beam at the implicit comparison between to FDR. “Today, in the second decade of the 21st century, we must take up the unfinished business of the New Deal and carry it to completion,” he said in an address at George Washington University last summer. Here in Iowa, he details in his stump speech what that continuation means: “Medicare for All” and free college and a Green New Deal and more.

He has long described himself as a democratic socialist. Sanders doesn’t mind socialist critiques. Neither does Nicole Khvalabov, who likes policies that flow from that ideology, even if it creates a little family friction.

A graduate student studying at the University of Iowa, Khvalabov points to her homemade earrings that bear images of the Vermont senator and boasts that she volunteered for Sanders in the last election. But each time she would leave her house to knock on doors, her parents always squawked: “Oh, that communist?”

And Khvalabov understands the reaction that Omar warned about: “I get why it scares some people. Both of my parents are from Soviet Russia.”

Her mom and dad find it difficult to accept Sanders because they naturally mistrust anything associated with an ideology other than capitalism. They fled the USSR in the 1980s, she explains, and they lecture her for not knowing what it is like to “live under something like that.” But Sanders is different, she insists, because “socialism doesn’t equal Soviet communism.”

“I still get why it scares people based on their experiences or the hysteria in the United States. I know why people can be afraid of the word,” she concludes. “I’m not.”

Most who show up for Sanders (and for Vampire Weekend) were not alive for the fall of the Berlin Wall, let alone the Cold War that preceded it. But they are not afraid of socialism -- the S-word that Republicans will deploy ahead of November no matter who the Democratic nominee is, but especially if it’s Sanders.

That is just fine with Danny Krug, a software engineer from Minneapolis who drove here to knock on doors for his preferred candidate. “You know what, man?” he says, shouting to be heard over the music. “They can be scared if they want, but my mom is 65 and she collects Social Security and she talks s--- on socialism all the time, but that’s what that is. At the end of the day, that’s essentially a socialist program.

“If that means taking care of sick people and mentally unwell people and not making them go bankrupt for treatment,” he continues, “then, I guess, sign me up.”

Many in the crowd in Cedar Rapids agree with that sentiment, and the Iowans are joined by supporters who travelled from Illinois and Indiana and New York and Ohio. Some are still trying to choose between candidates. Many are all-in for Bernie. All remember, or are at least reminded, of how the Democratic National Committee put its thumb on the scales for Hillary Clinton last time around.

Michael Moore made sure of this. The documentary filmmaker repeats his gripe about how the DNC allegedly changed the qualifying rules for the debates this time around so that Michael Bloomberg — “the billionaire Republican mayor of New York City,” as he puts it — could potentially qualify and crowd out Sanders. At this, the crowd boos. Loudly.

But those assembled are not ready for a revolt against the party — at least for now. They will play by and expect to win by those rules. Their revolution, they believe, can come at the ballot box. According to the RealClearPolitics average that Moore cites on stage, Sanders leads in Iowa and New Hampshire and California. They believe he can win the nomination outright. They will worry about the establishment another time.

So why harsh the mellow?

Saturday is a night for celebrating even before any results are tabulated. Harvard philosopher Cornel West is on stage, and so is Academy Award-winning actress Susan Sarandon. They are flanked by the rising stars of the left, Omar and Michigan Rep. Rashida Tlaib. It is the closest equivalent to a progressive Woodstock that Iowa will see before Election Day.

Sanders feels like dancing.

At the end of his remarks, the candidate boogies to Vampire Weekend with the assembled co-stars. Then he walks off the stage and toward the crowd, unconcerned with the “S-word” criticism that is sure to keep coming. Adoring supporters surge forward. Security guards brace the barricades, just to be safe.

The headliner of the night later covers Thin Lizzy’s “The Boys are Back in Town,” and Sanders, no doubt, hopes that he and his democratic socialism are better received in 2020 than last time around.