It was the first high-profile incident since Zohran Mamdani’s election involving one of New York City’s most sensitive flash points: the conflict between Israel and the Palestinians. A rowdy protest descended last Wednesday on Park East Synagogue, one of New York’s most prominent Modern Orthodox congregations, which had rented space to an organization that helps Jews move to Israel as well as to settlements in the occupied West Bank. Chants of “death to the I.D.F.” and “globalize the intifada” rang through the air. Mr. Mamdani, the mayor-elect, responded the next day, saying through a spokeswoman that he “discouraged the language”...