The verdict of the rabbi of a prominent Manhattan synagogue after meeting with the incoming mayor, Zohran Mamdani, bodes ill for New York City’s Jewish community. Rabbi Ammiel Hirsch of the Stephen Wise Free Synagogue — a distinguished liberal institution — disclosed on Friday his view that Mr. Mamdani harbors not merely a political opposition to Israel but a deep-rooted hostility that will soon command the powers of City Hall. 

“While we were pleased to be able to discuss our concerns with the mayor-elect, those concerns remain,” Rabbi Hirsch wrote on X following Thursday’s parley with Mr. Mamdani and a dozen other rabbis.“We’ve never before had a mayor who has expressed this kind of ideological hostility to the very existence of Israel. It is not about policy differences; rather, it is about the denial of Israel’s right to exist as a Jewish state at all.” 

Rabbi Hirsch wrote in his post that he continues “to worry deeply about the upcoming four years.” During the meeting the rabbi told Mr. Mamdani that “anti-Zionist rhetoric and anti-Israel policies will threaten Jewish safety in NYC and will, inevitably, lead to an unproductive and tense relationship with the Jewish community,” he wrote. The Jewish community, he vowed, “will energetically oppose any and all anti-Israel rhetoric and action.”

The rabbi declined to share specifics of the discussion though before the meeting two participants told CNN they planned to press Mr. Mamdani to “back away from his rejection of Israel’s right to exist as a Jewish state” and reverse his support for the boycott, divestment, sanctions movement. That Rabbi Hirsch emerged from the conversation still warning of threats to Jewish safety tells us how that went. 

Telling, too, is the timing of Rabbi Hirsch’s post on X. It came hours after Jewish Insider published an account of the meeting under the headline “Rabbi Ammiel Hirsch, outspoken backer of Israel, leaves meeting with Mamdani ‘encouraged.’” That encouragement, as it turns out, was over Mr. Mamdani’s willingness to go “into meetings with people who have significant disagreements with him.” 

Showing up is one thing. Opening one’s mind to change is quite another — and Mr. Mamdani has given us little reason to believe he sees moderation in his future. Feature his response to protesters who surrounded a Manhattan synagogue chanting “Death to the IDF.” Mr. Mamdani declined to condemn the activists, instead suggesting the event inside, which promoted Jewish immigration to Israel, was “in violation of international law.”

Mr. Mamdani’s next big test comes upon his accession as mayor. It was set up by Mayor Eric Adams earlier this month when he issued an executive order barring the city from divesting from Israel. Mr. Mamdani has long championed BDS, and when asked in November whether he would impose such policies, he didn’t rule it out. “I would support and have supported non-violent movements to bring about compliance with international law,” he said. 

The question is no longer whether Mr. Mamdani holds views that are fundamentally hostile to Israel — Rabbi Hirsch has made that abundantly clear. The question is whether those convictions will translate into policy and whether New York’s Jews will spend the next four years fighting their own mayor. Mr. Adams’s executive order forces an answer. How Mr. Mamdani responds will tell us what New York needs to know about the administration to come.