By Jonathan Mahler

New York Times

She had seen her face superimposed on the body of a concentration camp inmate. She had been called “a slimy Jewess.” She had been told she “deserved the oven.” One anonymous individual had electronically harassed her for 19 hours straight.

Things got so bad that Bethany Mandel, a 30-year-old freelance writer in Highland Park, N.J., decided one afternoon last spring to drive to a nearby gun shop. A mother of two small children, she now keeps a .22 in her home.

What had she done to provoke so much vitriol? She posted some messages on Twitter drawing attention to the fact that Donald Trump seemed to have a lot of anti-Semitic supporters.

In some respects, Mandel’s story has become a familiar one. She is among hundreds of Jewish journalists who have been the target of anti-Semitic attacks on Twitter during the 2016 presidential campaign, according to a new report by the Anti-Defamation League.

Anti-Semitism has been resurgent in Europe for years. But it has taken on a new dimension in the United States with the emergence of the Trump campaign, whose battle against political correctness has provided a kind of on-ramp for bigotry to enter the political mainstream.

During its investigation, the organization found that 2.6 million anti-Semitic messages were posted on Twitter from August 2015 to July 2016. Of those, 19,253 were directed at journalists.

There was a significant uptick starting early this year, when the presidential campaign began to intensify, the organization said in its report, to be released on Wednesday. More than 800 journalists have been the subject of anti-Semitic attacks on Twitter, with 10 of them receiving 83 percent of the total attacks.

The words appearing most frequently in the Twitter biographies of the attackers were “Trump,” “nationalist,” “conservative” and “white.” Many of the owners of the 1,600 Twitter accounts were anonymous though at least two are prominent white supremacists: Andrew Anglin, founder of the website The Daily Stormer, and Lee Rogers of the Infostormer.

The report was careful not to suggest that the Trump campaign “supported or endorsed” the anti-Semitic attacks, but noted that many were sent by his supporters.

But some of the targets said that by evoking hostility toward minorities, Trump’s campaign had inspired and emboldened white nationalists and others to engage in acts of digital aggression toward “others” — including Jews — and toward Jewish journalists in particular.

“The best analogy I can give is that the campaign turned over a rock, and a lot of stuff began crawling out from under it,” said John Podhoretz, the editor of Commentary magazine. “There were these code words and dog whistles that let it appear that people who had been doing things in the shadows could now start marching forward.”

Many of them have marched directly onto Twitter, no doubt because of its unique place in the political conversation: as a popular site for journalists, but also one of Trump’s favorite modes of communication, and thus a gathering place for his supporters.

“What I worry about is that this portends something very dangerous for our democracy,” said Jonathan Greenblatt, chief executive of the Anti-Defamation League. “This is not just about anti-Semitism directed against Jews. The bigger story is the threat to free speech and the threat to a free press.”

The report was also critical of Twitter for only not deleting or at least suspending the accounts of the vast majority of the offenders.

“We’re seeing in a very coordinated way this kind of hate, and what we are not seeing are the platforms — in this case, Twitter — stepping up and dealing with it,” said Greenblatt.

In a statement, a Twitter spokesman noted that the company’s policy prohibits anti-Semitic content and that it planned to introduce new policies and tools to assure that its users felt safe in the coming weeks.

“We have no knowledge of this activity and strongly condemn any commentary that is anti-Semitic,” Hope Hicks, a spokeswoman for the Trump campaign, said in a statement responding to the report. “We totally disavow hateful rhetoric online or otherwise.”

While Trump and his campaign have not leveled any explicitly anti-Semitic attacks at journalists, he has trafficked in some anti-Semitic stereotypes. In July, he posted an image on his Twitter account of a six-pointed star next to Hillary Clinton, with money seeming to rain down in the background. Facing criticism, he deleted the tweet, but then said he regretted having done so.

And in a speech last week in West Palm Beach, Fla., he accused Clinton of guiding a “global power structure” that has conspired against the working class — prompting a scolding on Twitter by Greenblatt.

Whatever Trump’s intentions, his candidacy has been treated as a call to arms by white nationalists, who often rush to attack Jewish journalists when they write something perceived as unflattering about Trump.

After she wrote a profile of Trump’s wife, Melania, for GQ magazine, the journalist Julia Ioffe was deluged with anti-Semitic taunts on Twitter. One referred to her as a “filthy Russian kike.” When Melania Trump was asked about the controversy, she said that Ioffe had “provoked” her attackers.

Jonathan Weisman, an editor at The New York Times, has been sent, among other things, cartoon drawings of the hooknosed Jew and an image of the gates of Auschwitz against the words: “Machen Amerika Great.”

And when Ben Shapiro, a former editor-at-large at Breitbart, the right-wing news website, announced on Twitter the birth of his second child, he received this reply: “Into the gas chamber with all four of you.”

There is little evidence that these attacks are working, at least as an intimidation tactic. On the contrary, some Jewish journalists have added triple parentheses around their names on Twitter, taking what had been a way for denizens of the alt-right — an extremist fringe of message boards and online magazines popular with white supremacists — to identify someone as Jewish, and turning it into a badge of honor.

“It seems to me that when the Twitter Nazis hate you, you are probably doing something right,” said Jeffrey Goldberg, editor-in-chief of The Atlantic. “It’s when they like you — and here I’m thinking about a certain presidential candidate — that you might have a problem.”

© 2016 The New York Times Company