Laura Loomer continues her Periscope as she is escorted from the stage, on June 16th. Photograph via Charlotte Alter / Twitter

On Friday morning, Laura Loomer woke up early and took a Metro-North train from West Harrison, New York, where she lives, to Manhattan. She made her way to Central Park and secured a second-row ticket to that night’s performance of the Public Theatre’s production of “Julius Caesar.” Then she walked around the Upper East Side for a few hours, stopping to get her nails done (color selection: Blue My Mind). Loomer is twenty-four. During the 2016 Presidential campaign, she worked for Project Veritas, the right-wing sting operation run by James O’Keefe. Operating undercover, she performed various stunts—for example, on Election Day, she appeared at a polling station wearing a burqa and asked for a ballot under the name Huma Abedin. Two weeks ago, Loomer left Project Veritas for the Rebel, a video-heavy outlet based in Canada. (From its About Us page: “We don’t just report the news, we participate in it.”) After a few years of anonymous work, she was eager to find the spotlight.

When Loomer entered the amphitheatre and took her seat on Friday evening, she saw Jack Posobiec, a friend and fellow pro-Trump activist, sitting two rows back. To avoid attracting attention, they communicated via text message. “Are you here for the Cernovich contest?” he wrote, referring to the social-media activist Mike Cernovich. “Just stay tuned,” she responded. The previous day, Cernovich had issued a kind of challenge grant: he would donate a thousand dollars to anyone who disrupted the play. The production presents Caesar as a Trump-like figure, and depicts his violent death; Cernovich argued that, if such a depiction was a protected form of speech, then a protest against it should be, too. (Loomer admires Cernovich, but she claims that she had the idea to protest the play before he did.)

In Act III, Scene I, as Caesar was stabbed, Loomer started a Periscope video on her phone and strode toward the stage. “Stop the normalization of political violence against the right!” she shouted. A few members of the cast, prop knives in hand, broke character and walked toward her. “We’re not promoting it,” one actress said. “This is ‘Julius Caesar.’ ”

“Shame on the New York Public Theatre for doing this!” Loomer continued. “You guys are ISIS! CNN is ISIS!” Security officers led her out of the amphitheatre, and the audience cheered. Then Posobiec stood up and shouted, “Goebbels would be proud!” He, too, was removed. The play continued, with this line: “Liberty! Freedom! Tyranny is dead! Run hence, proclaim, cry it about the streets.”

Loomer, standing in the park just outside the amphitheatre, kept live-streaming on Periscope. “Shame on all of you!” she shouted. A male couple passed by, walking hand in hand. “Shame!” Loomer screamed in the direction of the theatre*, her voice cracking. “Shame!” One man turned to the other and asked, “Who is this crazy bitch?” Loomer didn’t seem to notice. The police arrived and asked her to place her hands behind her back. “I’m not resisting, officers,” she said. “Unlike the left.”

The police took Loomer to the 19th Precinct station house, on East Sixty-seventh Street. As she was booked and fingerprinted, the hashtag #FreeLaura started to trend on Twitter, and two Web sites began soliciting donations for her legal defense. Loomer was charged with misdemeanor trespassing and disorderly conduct, and was ordered to appear in court in August. By midnight, she was released from police custody. In the lobby of the station house, she delivered a “press conference” straight to her iPhone camera. “I’m not apologizing,” she said. “Honestly, I would do it again.” She claimed that reporters were waiting for her outside, but added, “I’m not going to be giving interviews today.”

Thirty minutes later, I met up with Loomer at a restaurant a few blocks from the station. She was at a table with Posobiec and Franklin Wright, a member of a “pro-Western fraternal organization” called the Proud Boys, whom she had hired earlier that day to act as her cameraman and personal security detail. “In the police precinct, a bunch of the cops were pulling up articles about me on their phones,” she said. “One of them told me, ‘We’re not supposed to say this, but we support what you did.’ ”

Posobiec and Wright ordered cheeseburgers; Loomer ordered a bowl of chili. There was silence as they scrolled through their Twitter timelines.

Sean Hannity, of Fox News, had tweeted approvingly about her, and she soon booked an appearance on his show. Laura Ingraham also tweeted her support, adding, “How many wd storm stage if ‘Obama’ was stabbed?” (In 2012, a Minnesota production of “Julius Caesar” did feature the assassination of an Obama lookalike, sparking no comparable outrage.)

Posobiec noted that a thousand-dollar donation to Loomer’s defense fund had just come in. He added, “You’re the No. 4 trending hashtag right now.”

“Amazing,” Loomer said. “Can you screenshot that and send it to me?”

“Of course,” Posobiec said. “You think this is my first day on Twitter?”

Loomer noticed that Ben Shapiro, a conservative columnist who opposed Trump during the 2016 election, had begun to argue that her action was not consistent with free-speech principles. “This obnoxious stupid snowflake crap is no better than the protesters who try to block college speeches,” Shapiro tweeted.

David French, another anti-Trump conservative, joined in. “Who is this guy French?” Loomer asked. “Is he a liberal?”

“He’s National Review,” Posobiec said.

“Oh,” Loomer said, rolling her eyes. “Who gives a shit about him?”

“They’re just jealous, man,” Posobiec said. “Ben Shapiro never even supported Trump. Just tweet at him, like, ‘Et tu, Brute?’ ”

“I was not blocking anyone’s speech,” Loomer said, her voice rising. “The play didn’t stop after they made me leave. If anything, I was increasing the amount of speech!”

Richard Spencer, a white nationalist who lost credibility with many right-wing activists after making a Heil Hitler-esque hand gesture while celebrating Trump’s election victory, began to criticize Loomer, also on free-speech grounds. He promoted a counter-hashtag: #LockUpLaura.

Loomer, who is Jewish, workshopped several possible rejoinders to Spencer, tweeting the ones that got the best response at the table. “You can't stand the fact that a Jew is in the spotlight,” she tweeted. Then, looking up, she asked, “I’m thinking of saying ‘1939 much?’ Or should I go with 1945?”

Posobiec, finishing his burger, said, “This is gonna go down as the greatest production of ‘Julius Caesar’ in history.”

Loomer nodded. “I redefined Shakespeare tonight,” she said. “A lot of people are doing great work from behind a computer screen, but I’m proud that I actually had the balls to show up and do something.” By the end of the night, she had gained twenty thousand Twitter followers and had received nearly ten thousand dollars in online donations. The Shakespeare scholar Stephen Greenblatt has argued that “Julius Caesar” should be read as a cautionary tale about the unforeseen pitfalls of political violence. But Loomer provided several rationales for her actions: that she had merely used words, whereas the left engages in actual violence; that she felt it was her patriotic duty to stop the play, which was “a form of terrorism” that would “bring us closer to civil war”; that the Public Theatre is “aligned with ISIS, politically.” The only incontrovertible fact was one that she never uttered aloud: that the stunt would do wonders for her personal brand.

A server approached the table. “I couldn’t help overhearing—what exactly did you do tonight?” she asked.

“I protested a play that was encouraging violence,” Loomer said.

“How, exactly? Did you do it before the play, or wait until after?”

“No, during,” Loomer said, her eyes cast down at her phone.

“Oh, O.K.” the server said. “Can I get you guys anything else?”

*This post has been updated to clarify that Loomer was shouting at the theatre.