The final straw was a report on Wednesday in the Washington Free Beacon, which found a Facebook post in which she used a vulgarity and described Mr. Netanyahu as “arrogant, deceptive, cynical” and “manipulative.”
The Sanders campaign’s announcement on Tuesday that Simone Zimmerman would be its national Jewish outreach coordinator delighted her fellow left-wing Jewish political activists and encouraged their belief that public expressions of disgust with the Israeli government had edged into the acceptable mainstream of Democratic politics.
They might have been getting ahead of themselves.
On Thursday, Senator Bernie Sanders’s campaign suspended Ms. Zimmerman, 25, after revelations that she had used vulgarities in Facebook posts about Prime Minister Benjamin Netanyahu of Israel and Hillary Clinton. The suspension, hours before a Democratic presidential debate in Brooklyn, made for an embarrassing misstep for Mr. Sanders, a secular Jew who, despite having lived briefly in Israel and being the most successful candidate of his faith in American history, is being pummeled by Mrs. Clinton among Jewish voters.
But the suspension was also an important moment in the small but deeply felt universe of Democratic Jewish politics, which has been torn apart on generational and ideological lines over the acceptable level of criticism of Israel’s right-wing government.
With Ms. Zimmerman’s history of opposition to Israeli policies in the West Bank and Gaza, her hiring drew concerted and ultimately overwhelming pressure from American Jewish leaders. Her suspension showed that when it came to the high stakes and intense scrutiny of presidential politics, the establishment’s view of Ms. Zimmerman and her brethren as dangerous radicals still held sway even with Mr. Sanders, a candidate promising a revolution.
“The fact that he acted shows that obviously he didn’t think it was acceptable,” said Malcolm Hoenlein, the executive vice chairman of the Conference of Presidents of Major American Jewish Organizations.
A chorus of Jewish figures, including Abe Foxman, the president emeritus of the Anti-Defamation League, had joined Mr. Hoenlein in calling for Ms. Zimmerman’s firing. The final straw was a report on Wednesday in the Washington Free Beacon, which found a Facebook post in which she used a vulgarity and described Mr. Netanyahu as “arrogant, deceptive, cynical” and “manipulative.” She then used more aggressive language and continued that he had “sanctioned the murder of over 2,000 people this summer.”
Michael Briggs, a spokesman for Mr. Sanders, wrote in an email, “She has been suspended while we investigate the matter.”
After Mr. Sanders won the New Hampshire Democratic primary in a landslide, Ms. Zimmerman also wrote triumphantly on Facebook, “The first Jew in history just won a primary, as a proud socialist calling for political revolution.” Then she criticized Mrs. Clinton and added a vulgarity.
Ms. Zimmerman declined to comment on her suspension, but supporters noted that she wrote the Facebook post about Mr. Netanyahu in March 2015, an emotionally charged time, when Mr. Netanyahu infuriated liberals across the United States by addressing Congress to argue against President Obama’s nuclear deal with Iran.