Self-described antifa activists John Cookenboo, left, and Vincent Yochelson in Oakland, Calif. (Nick Otto/For The Washington Post)

On the morning of the protest, Sean Hines woke with a sense of purpose he'd seldom felt. He was a 20-year-old high school dropout with no car, no job and no money. A year and a half ago, he'd been arrested for a drunken brawl. Now Hines was about to be arrested again, but for something he believed in.

In his Santa Rosa halfway house, Hines dressed in all black. He chugged an energy drink, popped some nicotine gum and climbed into a friend’s car that blasted German punk rock as it barreled toward Berkeley.

“Alerta, alerta, anti-fascista!” the chorus shrieked.

It was a call to arms for militant anti-fascists, or “antifa” — and Hines was heeding it.

But the Aug. 27 protest in Berkeley did not go according to plan. Police quickly arrested Hines and 12 others. Then, in images broadcast across the country, more than 100 antifa activists leapt over barricades and stormed Martin Luther King Jr. Civic Center Park, attacking a handful of President Trump supporters and right-wing activists.

Left-wing counterprotesters clashed with right-wing protesters and Trump supporters on Aug. 27 in Berkeley, Calif. Violence erupted when a small group of masked antifa and anarchists attacked right-wing demonstrators.

A month earlier, few Americans had heard of antifa. Then came Charlottesville, where antifa activists were credited with protecting clergy members from attacks by white supremacists.

The violence in Berkeley led to a backlash, including from the left. The city’s mayor, a Democrat, called for antifa to be classified as a gang and for the University of California at Berkeley to cancel conservative speeches later this month to avoid more violence.

Black-clad antifa members attack right-wing demonstrators in Berkeley

In Washington, where antifa smashed storefronts and torched a limousine on Inauguration Day, authorities fear the far-left activists will strike again Saturday, when the Mall will host the “Juggalo March” — a gathering of fans of the rap group Insane Clown Posse — and a pro-Trump event dubbed the Mother of All Rallies.

If Trump’s election has emboldened the far right, then it has also energized its enemies.

Hidden behind masks, however, antifa activists remain mysterious. Are they everyday citizens guarding against the rise of a Fourth Reich? Or are they, as Trump has claimed, merely the “alt-left” — a lawless mirror image of the white supremacists they oppose?

On Thursday, Trump claimed recent antifa antics had justified his much-criticized response to Charlottesville, in which he blamed the violence on “both sides.”

“I think, especially in light of the advent of antifa, if you look at what’s going on there, you have some pretty bad dudes on the other side also, and essentially that’s what I said,” he told reporters Thursday.

Interviews with a dozen antifa activists show they come from a variety of backgrounds and are only loosely affiliated. Some, like Hines, are youths in search of a cause. Others have been demonstrating for decades. Many are anarchists, although some vote. They employ a range of peaceful tactics, including doxing, or exposing, white supremacists. While they are all open to using violence, some embrace it — even glorify it.

What unites them is the belief that free speech is secondary to squashing fascism before it takes root in the United States.

“If everyone is punching a Nazi, it’s eventually going to create a mass militant movement based around anti-fascist,” Hines said. “That hopefully will be enough to stop them from gaining power.”

‘We’re each other’s enemy’

Among the scores of antifa who stormed the park that day in California were John Cookenboo, 27, and Vincent Yochelson, 23. The Bay Area natives began protesting against racism in 2009 when Oscar Grant, a 22-year-old African American, was shot in the back by a white Bay Area Rapid Transit officer. In the years since, they have attended dozens of demonstrations, including Occupy Oakland and Black Lives Matter marches.

Two years ago, Trump’s presidential campaign changed everything. White supremacists began holding rallies in the Bay Area. Antifa began confronting them — with force.

“There has been a galvanization of both sides,” Yochelson said. “We’re each other’s enemy.”

The same thing was happening across the country. On Inauguration Day, two incidents 2,000 miles apart hinted that the conflict — dating to standoffs between skinheads and anti-racists in the 1980s — had intensified.

Anarchists and antifa: The history of the activists Trump calls the ‘alt-left’

In Washington, a masked antifa sucker-punched Richard Spencer, a leader of the alt-right movement that seeks to create a whites-only “ethno-state.” Footage of the attack spawned Internet memes as well as a question many Americans seemed to take seriously: Is it okay to punch a fascist?

The same day, an anti-fascist protester was shot in the stomach, allegedly by a Trump supporter, during demonstrations against a speech by right-wing blogger Milo Yiannopoulos at the University of Washington in Seattle.

Whether Americans had heard of antifa or not, violence involving the far left and far right suddenly seemed to be everywhere.

Nowhere was it as intense and frequent as in Berkeley.

On Feb. 1, dozens of antifa smashed windows and lit fires on the UC-Berkeley campus, leading the school to cancel a speech by Yiannopoulos. A month later, Trump supporters and white supremacists responded by gathering in MLK Park for a free-speech rally.

Armed with military-grade riot gear, shields and walkie-talkies, Cookenboo and Yochelson were among the antifa to meet the rallygoers in what would become known as the first “Battle of Berkeley.” Videos from the March 4 melee show both sides carrying weapons. Kyle Chapman, the founder of the right-wing group the Fraternal Order of Alt-Knights, was later charged with a felony for allegedly wielding a leaded stick.

“I can’t get into too many specifics, but there was definitely an atmosphere of violence that day,” Cookenboo said. “Several people were injured, and me and Vincent pulled some people back from the line, pretty bloodied up.”

On April 15, Cookenboo and Yochelson were walking to the same park to confront many of the same right-wing protesters when they were arrested on suspicion of wearing masks while committing a criminal offense. Police also suspected Cookenboo of inciting a riot and possessing a switchblade knife. Charges have yet to be filed.

“I think they saw a group of people walking toward the protest in a lot of gear and felt that this point was the only time they’d really be able to interdict us,” Cookenboo said.

While they were in custody, Hines was in the fray for the first time.

“I did get pepper-sprayed in the face once, but I enjoyed it,” he said of the second “Battle of Berkeley.” “I’m a bit of an adrenaline junkie, so things like that kind of excite me.”

For Hines, antifa is the latest in a succession of left-wing causes. He first took an interest in anarchism four years ago. At one point, he was aligned with the Irish Republican Army. He now calls himself a “libertarian socialist,” communist and antifa.

He said the movement has helped him through a difficult 18 months. In April 2016, he dropped out of high school about the time he assaulted a Whole Foods security guard.

“I tried to steal a bottle,” he said. “I was pretty out of it.”

Hines, who said he suffers from addiction, completed a diversion program and the charges were dropped. He has spent the past six months in halfway houses, where he has a curfew and must pass nightly breathalyzer tests. He was logging hours each day on Facebook, debating politics. Eventually, he decided to stop debating and act.

“I wanted a purpose. I wanted an identity. That’s the reason why I became part of antifa,” he said. “I wanted to fight for something.”

Like many in the antifa movement, Hines says that had more people joined far-left militants in fighting fascists in prewar Germany and Italy, Adolf Hitler and Benito Mussolini never would have come to power.

Asked whether that comparison glorified today’s antifa violence, Hines said: “It needs to be glorified. We need to attract people to our side.” He was unconcerned that skirmishes could escalate into shootouts. “At least in that way we’d be able to fight back,” he said.

Antifa veterans are wary of newcomers raring for a fight, however.

“A lot of people are coming into antifa because of the thrill of violence, and that’s not what we’re about,” said Mike Isaacson, an anarchist PhD student and adjunct professor at John Jay College of Criminal Justice. “Anti-fascists are community oriented, and we do make the effort to keep everyone as safe as possible.”

In some cases, antifa have unwittingly attacked bystanders, even sympathizers. Cookenboo is keenly aware that not everyone on the other side is a fascist — his father voted for Trump. He and Yochelson grew up in middle-class households, attended some community college and hold steady jobs: Cookenboo at a marijuana processing plant, Yochelson at a catering company and a Unitarian church, where he is a chef.

The antifa movement isn’t “some strange, cloaked organization,” Yochelson said. “It’s your neighbors.”

He and Cookenboo say a feeling of powerlessness drives the antifa movement and its opponents.

“The people on the far right have . . . a sense that their country is being stolen from them, and that’s what Donald Trump has seized upon,” Cookenboo said.

“On the left, it’s an opposite but different story,” he continued. “I see all these videos of people being very racist to minorities on public transit or in grocery stores or anywhere that they can. We see this resurgence. And I can’t do anything to help those people, though I want to. So the only thing I can really do when these things happen is to go out and march in the street.”

‘Crawl back into the rat holes they came out of’

Video: What is the black bloc? (Video: Gillian Brockell/The Washington Post)

When Cookenboo and Yochelson arrived early to survey the scene on Aug. 27, they found MLK Park quiet. A “No to Marxism in America” rally had been canceled, and there were few right-wing protesters. So they decided to leave their riot gear in the car.

A few hours later, thousands of counterprotesters, including clergy members and a Holocaust survivor, peacefully marched to the park.

Then antifa arrived.

“It was actually a really great event. There was tons of solidarity and tons of people from across the political spectrum,” said Molly Armstrong, co-chair of the East Bay chapter of Democratic Socialists of America, who gave a speech linking white supremacy to capitalist alienation. “But a handful of people were violent, and that’s what everyone wants to focus on.”

The violence didn’t just overshadow the counterprotest, however. It exposed a deep divide within the left over the antifa movement.

Antifa were more concerned with "elevating their self-image" and "appearing heroic" than doing "less glamorous" work that might lead to real change, anti-capitalist columnist Chris Hedges wrote for Truthdig.

In a student newspaper op-ed, UC-Berkeley alumnus Mitchell Zimmerman compared the antifa movement to the Weathermen, a leftist extremist group that carried out bombings in protest of the Vietnam War. "We've seen it before," he wrote, "young people whose infatuation with violence undermines the progressive cause."

Rather than prevent fascism, antifa violence could further it, argued Laurie Marhoefer, an assistant professor at the University of Washington who has studied Hitler’s rise.

"Violent confrontations with antifascists gave the Nazis a chance to paint themselves as the victims of a pugnacious, lawless left," she wrote for the Conversation. "They seized it."

Yvette Felarca denies the antifa movement plays into its enemies’ hands. The diminutive middle school teacher has become the face of anti-fascism in the Bay Area. She said she was cut on the arm when her group, By Any Means Necessary, and antifa activists confronted white supremacists in Sacramento last year. She is facing a felony assault charge over the clash.

Speaking shortly before she led a protest on Berkeley’s campus this month, Felarca said antifa aggression on Aug. 27 ensured she wasn’t attacked again.

“They should be forced to crawl back into the rat holes they came out of,” she said of white supremacists. “Charlottesville showed [they are dangerous]. We can’t have another Heather Heyer” — a reference to the woman killed when a vehicle plowed through counterprotesters there.

The antifa movement should be seen in the context of rising intolerance on the left, particularly on college campuses, said Mark Peterson, a professor of public policy, political science and law at UCLA. This intolerance is ironic, he said, because decades ago, it was suspected leftists who were barred from universities and blacklisted from Hollywood.

“So it can’t simply be left to a young and not particularly well historically informed group of people to say, ‘We get to determine who’s a fascist and . . . do whatever we want to them,’ ” he said.

Cookenboo and Yochelson said they didn’t witness the Aug. 27 attacks but acknowledged they probably weren’t necessary.

“In this particular instance, it looked a little bit — what’s the word?” Cookenboo asked.

“Excitable,” Yochelson said.

The backlash spurred them to speak to the media about antifa, but that then led to death threats. Yochelson, who wears a bullet as an earring, said he wasn’t worried. Neither was his friend.

“I’ve taken steps to protect myself,” Cookenboo said, adding that he owns a shotgun and an AR-15 rifle.

But the violence also tarnished the 13 people arrested on mostly minor charges that day. None of the arrests was in connection to the dramatic assaults captured on camera, which happened after police had retreated, allowing antifa to overrun the park.

“The news coverage the next day was all about ‘violent antifa’ and then they showed our mug shots,” said James Dominic, 23. The son of a Marine veteran, Dominic said he is anti-fascist but not antifa. He went to the park as a medic in case anyone was attacked by white supremacists and was arrested for handing out surgical masks. He blamed the media, not antifa.

Hines said he didn’t mind being connected to the mayhem. When he was detained for wearing a mask in violation of city code and resisting arrest, a journalist asked him whether he had come to be violent. “I can neither confirm nor deny that,” he said with a smile.

Four days later, Hines said his only regret was that he was arrested before things got interesting.

“Most people I know love me now,” he said, sitting on a couch in his halfway house in front of a bowl of cigarette butts. “I’m not trying to brag, but I’ve become pretty popular.”

Perry Stein and Julie Tate contributed to this report.