A group of mostly young men began descending on the Brooklyn home of a Hasidic journalist just before midnight on Sunday.
The men, who were fellow ultra-Orthodox Jews, were shouting that the journalist, Jacob Kornbluh, was a snitch, an informer who had betrayed his own by publishing reports on how devoutly religious Jews in the city had been ignoring coronavirus guidelines.
The group got all the way to Mr. Kornbluh’s doorstep, where a line of police officers kept them at bay.
The tense scene spoke to what many Orthodox leaders said they had been seeing for weeks: a growing, raucous faction of young men in the community, tired of pandemic guidelines and resentful of the secular authorities, who are taking their cues from the broader right-wing movement in society, including from President Trump.
For months, misinformation and rumors about the virus, some inspired by Mr. Trump, have spread widely in forums like WhatsApp that are popular with ultra-Orthodox New Yorkers, according to numerous interviews with Hasidic leaders and community members.
Now, a new shutdown in Orthodox neighborhoods in Brooklyn and Queens, ordered last week by Gov. Andrew M. Cuomo, appears to have inflamed sentiments further. Mr. Cuomo closed nonessential business and schools, and limited attendance to 10 people at a time in houses of worship in the hardest hit areas, including synagogues.
Mr. Cuomo was spurred by spiking caseloads in the Orthodox community and concerns that health rules were not being followed. But some Orthodox voices have responded by arguing that their community’s religious life was being targeted by the government.
The Orthodox Jewish community in the New York region includes Hasidic and other ultra-Orthodox groups. There are as many as 500,000 ultra-Orthodox Jews in the New York region, and they have long tended toward conservative politics. In 2016, Hasidic neighborhoods in Brooklyn voted overwhelmingly for Mr. Trump.
But the pandemic may have also emboldened more extreme elements, complicating efforts to curb the virus and frightening normally outspoken Hasidic activists and writers.
“There is a mistrust in media, a mistrust in government, and people don’t check the facts,” Mr. Kornbluh said in an interview. “In the years since Trump came onto the scene, people are more engaged in politics, and follow Trump and his conspiracy theories.”
After the virus devastated Hasidic neighborhoods in the early days of the pandemic, many residents began to believe that safety precautions were unnecessary because they had developed herd immunity, according to community leaders.
That attitude, which health officials say has no basis in fact, has been a primary reason for a recent surge of cases in Brooklyn and Queens that has raised the citywide positivity rate to levels not seen in months.
On the first night after the governor announced the restrictions, a group of mostly young men in the predominantly Orthodox neighborhood of Borough Park took to the streets in protest.
They were led by a local radio host and viral video personality, Heshy Tischler, a Trump follower and a candidate for City Council who was once convicted of conspiracy to commit immigration fraud and sentenced to a year and a day in federal prison.
Mr. Tischler identifies as Orthodox, but is not part of a Hasidic sect. Still, he has gained popularity during the pandemic, in part because he has gone after critics of the Hasidic community.
The ultra-Orthodox communities in New York are an insular world that distrusts outsiders and disdains members who speak up in public about sensitive issues, like education or public health.
Since March, Mr. Kornbluh, a reporter for Jewish Insider who has lived in Borough Park for 18 years, has been posting on Twitter about the disregard for coronavirus safety measures in these communities.
On the second night of protests — where some waved pro-Trump banners — the crowd spotted Mr. Kornbluh, who was covering the events, and pointed him out to Mr. Tischler.
Mr. Tischler, unmasked, approached Mr. Kornbluh, and began calling him a traitor. Soon Mr. Kornbluh was surrounded by men and teenagers who shoved him against a wall, punched, kicked and struck him with objects, and then chased him for two blocks. Videos of the attack quickly appeared on social media.
Mr. Kornbluh said many in the group told him that he deserved to die and called him “Nazi” and “Hitler.”
“They were saying I am not part of this community and I should leave,” Mr. Kornbluh said.
Mr. Tischler was arrested on Sunday in connection with the attack. After he was taken into custody, a group of men showed up at Mr. Kornbluh’s home.
Mr. Tischler was arraigned on Monday on charges including inciting a riot and was released without bail. He returned home, where a boisterous crowd of young Hasidic supporters awaited him.
Standing on his porch, he plugged his candidacy for City Council and declared that he did not condone violence.
“We’re going to continue our fight,” he said. “We’re going to beat that Mayor de Blasio, we’re going to knock Cuomo out!”
The turmoil is also revealing a fault line through ultra-Orthodox New York over the question of how much the government — and the pandemic — should be allowed to intrude on religious life. In March and April, rabbis vigorously debated about whether synagogues should close in compliance with Covid-era restrictions or whether communal prayer must continue, according to Yochonon Donn, a Hasidic journalist.
But in recent months, as the pandemic has grinded on and a new outbreak has brought renewed restrictions, the question of how to respond is playing out in the street and online, forums where the influence of rabbis is limited but where Mr. Tischler’s theatrical videos have been shared widely.
While local leaders and elected officials have denounced the violence at last week’s protests, relatively few have condemned Mr. Tischler.
Rabbi Chaim Dovid Zwiebel, executive vice president of Agudath Israel of America, an Orthodox umbrella group, said Mr. Tischler was a fringe figure who had “made an idiot of himself.”
“I don’t think anybody really knew him or had heard of him until he decided to turn himself into the wonderful spokesman he thinks he is,” Rabbi Zwiebel said. “This guy is supposed to be a community leader? Please. It is an embarrassment.”
Mr. Tischler first gained popularity in June when he used bolt cutters to unlock city playgrounds — at least 14 in his telling — that had been closed by the authorities as part of Covid-19 restrictions. The move was celebrated by Orthodox parents, many of whom had been crowded in small apartments with many children.
In an interview in Crown Heights last week, Mr. Tischler said he believed the newly imposed restrictions were singling out Orthodox Jews because “the Jews don’t fight back, the Jews take things lying down.”
“We will not be sheep anymore,” he said.
He called Mr. Trump one of the “greatest presidents we’ve ever had” and said he thought Mr. Cuomo was exaggerating the threat of the coronavirus because the governor planned “to create martial law.”
As he spoke, a small circle of young men gathered on the sidewalk to listen. One of them, Mendy Freidman, 23, shrugged when asked if he supported Mr. Tischler but said that he understood his appeal.
“Nobody else is willing to do what he does,” he said. “Nobody else is willing to go to jail.”
But Mr. Tischler’s public stunts often contain a hint of menace. Last month, when city health officials held a news conference in Brooklyn to discuss the virus uptick, he disrupted the event while not wearing a mask, shouting at top health officials that the virus uptick was fake, and called them “Jew haters” and “garbage.”
And his messages have carried racist undertones. Some of the city health workers sent to conduct outreach in Orthodox neighborhoods have been people of color. In one video, Mr. Tischler shows himself calling them outsiders who are “ready to come after us.”
“I’m sure most of them are from just the projects, picked off the street with not even proper training,” he said.
The criminal charges against him stem from his actions during the protests, which lasted for two nights last week and resulted in attacks on at least three men. Two of them, a photographer and a Hasidic man accused of disloyalty to the community, were attacked on Tuesday.
After those episodes, Mr. Kornbluh sent Mr. Tischler a late-night WhatsApp message, which was shared with The New York Times, calling the violence Mr. Tischler was stoking a “chillul Hashem” — a desecration of God’s name.
The next morning, Mr. Tischler filmed a video of himself in a graveyard threatening Mr. Kornbluh, which soon spread in popular Hasidic WhatsApp groups.
That night he confronted Mr. Kornbluh at the protest, setting off the mob attack that resulted in Mr. Tischler’s arrest on Sunday, prosecutors say.