Bernie Sanders visits Boston for three sold-out events Friday

Bernie Sanders spoke at the Iron Workers Local in February 2016. Suzanne Kreiter/Globe staff

Apparently Boston is still really feeling the Bern.

Senator Bernie Sanders of Vermont, whose failed presidential campaign started a “political revolution” that catapulted him into the national spotlight, comes to Boston Friday for a whirlwind day of appearances, most of which appear to be already at capacity.

Sanders will give a speech and take questions at the Edward M. Kennedy Institute for the United States Senate at 2 p.m. in Dorchester. The conversation, moderated by the Globe’s James Pindell, is sold out, according to the institute’s website.

Sold out, too, is Sanders’ event Friday night at Orpheum Theatre in Downtown Crossing, where he will take the stage with Senator Elizabeth Warren of Massachusetts, bringing together two of the nation’s leading progressive politicians.

According to Our Revolution, the political nonprofit hosting the free event with Raise UP Massachusetts and the Jobs Not Jails Coalition, the theater’s capacity is 3,500, which is how many people have registered for the rally.

“The guy, who is not even a Democrat, is being treated like a rock star in deep-blue Kennedy Massachusetts, and it’s because he is a rock star,” said Erin O’Brien, chairwoman of the political science department at the University of Massachusetts Boston. “It speaks to the vacuum that Hillary Clinton left. She never had the same kind of passionate support that Bernie Sanders had.”

Sanders, an independent and self-described democratic socialist, has represented Vermont in Congress since 1991. But he caucuses with the Democrats in Congress and campaigned in the Democratic presidential primary against Clinton, who won the nomination and whom Warren eventually endorsed.

Sanders and Warren have worked closely in the Senate, especially since Donald Trump won the White House in November. But many of Sanders’ supporters were disappointed that Warren didn’t endorse his presidential campaign in 2016.

“A lot of Bernie supporters felt if Elizabeth would have gotten behind him, he would have done better” in the primary, O’Brien said. Their joint appearance Friday night “shows that the endorsement days are over,” she said.

The Friday night rally, to champion causes such as criminal justice reform, immigrants’ rights, and wage inequality, does something else, political scientists say. It helps Warren as she gears up for reelection in 2018, which at least one recent survey shows might not be a cake-walk.

A poll released in January by WBUR-FM showed that 46 percent of respondents said it was time to “give someone else a chance” when asked if Warren deserved to retain her seat. About 44 percent of voters said that Warren should get another term.

“Sanders is surely invested in helping Warren win reelection,” David Hopkins, a political science professor at Boston College, said in an e-mail.

Hopkins called Sanders a “kindred spirit in the Senate” for Warren. If she wins reelection in 2018, Warren becomes a potential presidential candidate in 2020, he said.

“If she does run, she would likely pattern her presidential campaign after Sanders’ 2016 candidacy and seek to inherit the faction of Democrats who supported Sanders last year,” he wrote.

Also on Friday, Sanders also will make a quick jaunt across the Charles River between speaking engagements at the Kennedy Institute and the evening rally. In Cambridge, he will attend a book-signing at the Massachusetts Institute of Technology.

That event is — you guessed it — sold out, too.