CEDAR RAPIDS, Iowa—“Ice-cold beer and water! Get your ice-cold beer and water!”

The beverage vendor stepped assertively through the shoulder-to-shoulder general-admission crowd, balancing a massive plastic container filled with “Ice-cold beer and water!” on top of his head as smoke machines belched out a hazy fog that gave the flashing LED lights a gauzy quality. As he passed, a trio of teenage girls assertively moved to fill the gap in his wake so they could get that much closer to the stage, where in a few minutes, the man that they and thousands of others had come to see would cross the stage and take the mic.

“Oh my God,” one girl said to her friends. “I can’t believe he’s actually here!”

But the object of their obsession wasn’t a rock god, although there were plenty in the house here at the U.S. Cellular Center arena in downtown Cedar Rapids. It was Sen. Bernie Sanders, whose rally on Saturday night had all the trappings of a top-flight music festival, complete with a killer lineup of opening acts, a headliner at the apex of his long career, and a packed house of 3,000 screaming fans.

Though the rally had been pitched as a sort of Bernie-chella, with indie rock band Vampire Weekend headlining the “caucus concert,” the substance of the rally was pure Sanders stump speech, with the added flavor of the kind of high-wattage progressive surrogates that every other presidential candidate would do anything for.

“We are the campaign of energy—we are the campaign of excitement,” Sanders told the crowd, to raucous cheers that rose to a roar every time he pledged to fight for a new progressive policy as president, from cancelling student-loan debt to legalizing marijuana via executive order. “All over the world, people are looking to Iowa.”

The blending of a free rock concert with a left-wing political convention was a stark contrast from the more sober closing arguments being made by former Vice President Joe Biden, and the audience’s reception to Sanders’ booming voice rose in volume to meet it.

The audience had, after all, spent the better part of two hours being pumped up by “opening acts” in the form of progressive political royalty. In his speech introducing Jane Sanders, the senator’s wife, left-wing political activist Dr. Cornel West namechecked Jane Austen, Hebrew scriptures, Nina Simone, and Cesar Chavez; after she’d taken the stage, Sanders encouraged the audience to have a party both before and after the caucus, if that was what it took to get out supporters for her husband’s campaign; in a panel discussion, Rep. Ilhan Omar (D-MN) told the crowd that the free concert was just the beginning of a revolution that would shake the power of the elite few for good.

“Once we are in a fight to uplift one another,” Omar said, “we are going to have a better America that obstructs their ability to exploit us.”

Although some members of the audience seemed antsy for the policy discussion to end and for Vampire Weekend—specifically, dreamy frontman Ezra Koenig—to take the stage, many attendees told The Daily Beast that they were there for Sanders before any musical act.

“It’s not Vampire Weekend, featuring Bernie Sanders,” said Kane Patrick, a 21-year-old Sanders supporter with a septum piercing who had come from Nebraska to see the senator speak. “It’s Bernie Sanders, featuring Vampire Weekend.”

Shayna, a high schooler from nearby Iowa City, told The Daily Beast that she would have attended the rally no matter who was joining Sanders onstage, even though she’s too young to caucus for any presidential candidate.

“I think it starts with Bernie and, like, yeah, he is a good leader and a good figurehead,” said Shayna, who did not want her last name included because her mom thought she was staying over at a friend’s house instead of attending a rock concert-slash-political rally. “But his motto about it being ‘not me, us’ means that we all get, like, a stake in all the things he wants to do—I feel like he’s asking me to keep running in the marathon, because no matter how far he gets, there’s gonna be more to do.”

Those comments echo a constant and somewhat self-contradictory refrain from Sanders’ most diehard supporters here in Iowa: that while “we are a campaign of us, not me”—a clever repurposing of Hillary Clinton’s “I’m With Her” slogan from 2016 that stuck—at the end of the day, he is this movement’s leader, a position that even his flashiest surrogates and supporters can’t outshine.

Omar and Reps. Ro Khanna (D-CA) and Pramila Jayapal (D-WA), for example, got the requisite applause lines for their progressive policy proposals, but no thunderous applause; one nearby attendee googled “Michael Moore” and read the filmmaker’s Wikipedia page aloud to friends to explain why he was onstage; actress and activist Susan Sarandon quietly appeared, with Sanders and the other surrogates onstage at the end of the senator’s speech, as if manifested by the left-wing energy in the room, as Vampire Weekend played a rocked-up version of “Takin’ It To the Streets” by the Doobie Brothers, before departing moments later without saying a word.

By the time the putative headliners transitioned into playing “Harmony Hall”—they sound great live, by the way—dozens of the rally’s attendees had already started heading for the exits.

“If this were the Bon Iver concert from last night I might have stayed,” joked Jaymie Sowers, referring to another free concert that the Sanders campaign hosted on Friday night in Clive, Iowa. “But I came here to see Bernie, and everything else is just, like… extra.”