Throughout most of his striking rise in the New York City mayoral race, Zohran Mamdani has attracted donors and young voters through a series of campaign-vérité videos, a breezy mixture of street wisdom and personality-driven, left-leaning messaging.

But on Friday, Mr. Mamdani found himself quickly preparing a far more sober video to defend himself against the false perception that he had refused to condemn the Holocaust.

His rapid response illustrated how a candidate’s stance on Israel and Jewish issues, especially during the divisive Israel-Gaza war, could carry outsize importance in the Democratic primary on June 24.

The primary comes at a precarious moment for the city’s Jewish community, the largest outside Israel. The Trump administration has cited concerns over antisemitism as a primary reason for cutting funding to elite universities and deporting and detaining students who have protested the war in Gaza.

Hate crimes against Jewish people are on the rise in New York City. In 2024, 52 percent of the reported hate crimes were against Jews, according to the police. The trend has continued in the first quarter of 2025, when 60 percent of hate crimes were committed against Jews.

The fallout is shaping the race for mayor. The UJA-Federation of New York, an influential Jewish service organization, is asking mayoral candidates on a survey if they will sign an executive order requiring all city agencies to “adopt and implement” the working definition of antisemitism from the International Holocaust Remembrance Alliance.