During a graduation speech at the City University of New York’s law school last month, Fatima Mousa Mohammed, a Yemeni American student, criticized “Israeli settler colonialism” and advocated for “the fight against capitalism, racism, imperialism, and Zionism.” Her words, which the university administration condemned as “hate speech,” kicked off a new round of public debate about the distinction between criticism of Israel and antisemitism. Republican members of Congress responded by introducing legislation that would deny federal funding to academic institutions that “authorize Anti-Semitic events.” The bill cites a definition of antisemitism that the Israeli government and its supporters have been...