In November, 2017, Kenneth Stern appeared before the House Judiciary Committee to testify about a bill under consideration, the Anti-Semitism Awareness Act. Approved by the Senate a year earlier, the bill would require the Department of Education to apply a specific definition of antisemitism when investigating alleged cases of discrimination against Jews on college campuses. Stern, a lawyer and scholar who served for twenty-five years as the American Jewish Committee’s in-house expert on antisemitism, had devoted much of his career to highlighting the hatred and intolerance that threatens Jews. He was also the lead drafter of the definition cited by the bill, a definition that he had once urged both State Department officials and foreign policymakers to embrace.

Yet, at the congressional hearing, Stern struck a different note. The definition, which had been written in 2004 and adopted, in 2016, by the International Holocaust Remembrance Alliance (I.H.R.A.), an intergovernmental organization based in Stockholm, was created to help governments collect data on antisemitism, he said. It “was not drafted, and was never intended, as a tool to target or chill speech on a college campus.” Stern was particularly concerned about a section of the definition that listed eleven contemporary examples of antisemitism, among them “denying the Jewish people their right to self-determination” and holding Israel to “double standards” that were not expected of other nations. As this language suggests, Stern believed that antisemitism could manifest as hostility to Israel and Zionism. But he also believed that enshrining such a definition into law would have dangerous consequences, exposing schools to civil-rights investigations simply for allowing lectures, protests, or programs that cast Israel in a negative light. In fact, some groups had already complained that courses critical of Zionism, and even films about Israel’s occupation of the West Bank, amounted to discrimination, based on the I.H.R.A. definition. The proposed bill was a clear threat to academic freedom, Stern warned, placing Congress in the middle of a debate that it had no business adjudicating.

To Stern’s relief, the Anti-Semitism Awareness Act failed to pass. But, two years later, in 2019, Donald Trump signed an executive order specifying that Title VI of the 1964 Civil Rights Act, which prohibits discrimination based on race, color, and national origin, would also bar “forms of discrimination rooted in anti-Semitism.” When enforcing such cases, the order held, federal agencies would consider the I.H.R.A. definition. Since the October 7th Hamas attack and the start of Israel’s war on Gaza, the number of Title VI cases alleging that Jewish students have been subjected to discrimination has risen dramatically. Thirty-three U.S. states and dozens of cities have now adopted or endorsed the I.H.R.A. definition. Many pro-Israel groups see this as an appropriate response to a surge of antisemitism, especially at universities, whose leaders, they claim, have failed to punish students who demonize Israel. According to a coalition of civil-rights and advocacy organizations that support Palestinian rights, including the Council on American-Islamic Relations and Palestine Legal, policing such expression is itself discriminatory. In a recent letter to Catherine E. Lhamon, the assistant secretary for civil rights at the Department of Education, the coalition cited numerous examples in which outside groups had invoked the I.H.R.A. definition to lodge “false accusations of antisemitism” against schools, pressuring them to cancel events such as a Palestinian literature festival that took place at the University of Pennsylvania in September.

Within the Palestine-solidarity movement, there is a widespread belief that defenders of Israel have used the I.H.R.A. definition to censor speech and silence legitimate criticism. What’s unusual about Stern is that he shares this concern despite being a defender of Israel himself. “I’m a Zionist,” he told me when we met recently at his home in Brooklyn, where he lives with his wife, Margie, a rabbi. Stern is seventy-one, with a scruffy white beard and a taste for casual attire. On the day I visited, he was wearing house slippers and nursing a slight cold. Since 2018, he has commuted frequently from Brooklyn to Annandale-on-Hudson, where he directs the Center for the Study of Hate, at Bard College. He’d had an unusually busy fall, in part because of the national debate about how universities should address the tensions fuelled by the Israel-Palestine war. Stern’s most recent book, “The Conflict Over the Conflict,” is about this very subject. Published in 2020, it received almost no attention when it came out, he told me. But, at a recent Jewish-studies conference, it was “selling like hotcakes,” and Stern suddenly found himself in high demand, fielding a slew of speaking invitations, media inquiries, and calls from university presidents asking him to address their boards. “It’s been crazy,” he said.