When Mayor Zohran Mamdani entered City Hall in New York, his plans for the Office to Combat Antisemitism prompted curiosity and some suspicion, given his stance as a fervent defender of Palestinian rights. As the mayor navigated the complex world of Jewish politics in the city, he committed to keeping the office, which was created by his predecessor, Eric Adams. Now he is preparing to announce its leader: Phylisa Wisdom, a fixture in Jewish political circles who runs the New York Jewish Agenda, a liberal organization that has criticized Israel’s conduct in Gaza. But unlike Mr. Mamdani, Ms. Wisdom believes...