Democratic presidential candidate Sen. Bernie Sanders (I-Vt.) listens to Rep. Don Beyer (D-Va.) before speaking to a crowd in Arlington, Va., Thursday. (Brittany Greeson/The Washington Post)

Northern Virginia got a taste Thursday night of the enthusiasm buoying the presidential campaign of Bernie Sanders, as the senator from Vermont drew a boisterous crowd to a policy forum in Arlington and railed against the political influence of the “billionaire class.”

Sanders singled out Republican White House hopeful Jeb Bush at the event, citing the unprecedented $114 million that the former Florida governor and an allied super PAC announced Thursday they had raised during the first six months of the year.

“This money is clearly coming from the wealthiest people in the country,” said Sanders, a self-described democratic socialist who has emerged as the leading rival to Hillary Rodham Clinton for the Democratic nomination. “There’s no accident that Jeb Bush and other Republican candidates who take huge amounts of money from the wealthy and the powerful come up with an agenda that represents the wealthy and the powerful.”

The event, sponsored by an array of Democratic and other left-leaning groups, was billed as a discussion of progressive policy issues and not as a campaign rally. It featured a second speaker on stage with Sanders, Rep. Don Beyer (D-Va.).

Still, the crowd of close to 500 people acted very much like the swelling audiences Sanders has seen on the trail, chanting “Bernie, Bernie, Bernie” and giving him two standing ovations before he even opened his mouth.

Once Sanders did address the crowd, he rattled off a now-familiar array of policy prescriptions, including raising the minimum wage to $15 an hour, expanding Social Security, guaranteeing health care as a right and providing free public college tuition paid for by a tax on Wall Street speculation.

He also promoted plans to guarantee workers family leave, paid sick leave and vacation time.

Almost everything Sanders served up was met with enthusiastic applause, with gun control being an exception. Sanders tangled with one audience member who questioned why he had voted for a bill to shield manufacturers from lawsuits brought by victims of gun violence.

Sanders, who represents a largely rural state with little gun control, cited other measures he had supported, including a ban on assault weapons and background checks. But he defended the vote in question, arguing that if someone hits another person with a baseball bat, it doesn’t make sense to sue the manufacturer of the bat.

Speaking more broadly of gun control, he said, “There has to be some give on both sides,” suggesting some policies might make more sense in urban areas than rural areas.

In recent weeks, Sanders has drawn some of the largest crowds of the 2016 presidential cycle. There were about 10,000 people in Madison, Wis.; more than 7,500 in Portland, Maine; more than 5,000 in Denver; more than 3,000 in Minneapolis; and more than 2,500 in Council Bluffs, Iowa.

Sanders’s campaign said it had not promoted Thursday night’s event to its supporters through e-mail or social media, and organizers said they stopped accepting RSVPs more than a week ago when they reached about 600 — more than the capacity of the auditorium.

People who inquired in recent days about attending had been told they’d be turned away, organizers said.

Beyer, a freshman congressman from the Alexandria area and a former lieutenant governor of Virginia, joked about the pro-Sanders bent to the audience. “Thank you all for coming out tonight just to hear me speak,” he said at the outset of his remarks.

Kay Burnett, who works at the CIA, was among the early arrivals Thursday night, taking a seat near the front of the auditorium.

“I didn’t want to be in the middle of a mob,” said Burnett, 74, who lives in Arlington and was seeing Sanders in person for the first time. She said she has yet to settle on a presidential candidate to support and wanted to hear what the senator had to say.

Ernie Lehmann, another early arrival, was leaning in Sanders’s direction when he walked in the door.

“I like his position on the disparity of wealth,” said Lehmann, 81, a retired educator who used to lead a teachers union.

Lehmann was wearing a “Sanders for President” T-shirt but had turned it inside out, out of respect for the event being billed as a policy discussion rather than a campaign rally. Before leaving, he had turned it back the other way.