In the closing days of the campaign, Mamdani, who began his activism journey as a Students for Justice in Palestine leader at Bowdoin College, defended the term “globalize the intifada” as an expression of Palestinian rights. Mamdani’s defense of the phrase was strongly criticized by Jewish groups across the ideological spectrum, who view the phrase as a call to violence. While Mamdani has pledged to keep Jewish New Yorkers safe, he has not acknowledged their concerns about his invocation of a phrase tied to a violent, yearslong Palestinian uprising.

“Biden was elected running a campaign in 2020 premised on combating antisemitism. That was the animating feature that got him into the race. So the politics of this have really moved,” said the former White House official. “This is all about language and people using their microphones, and the fact that someone could feel empowered to double down on these ideas and win a mayoral race in New York City, that doesn’t happen by accident. It takes years of moving the goalposts on this language, on what it means to be antisemitic in America in 2025.”

This Biden administration staffer, who requested anonymity for fear of professional backlash, is one of many Jewish Democrats questioning where their party is heading after a dynamic young socialist with radical anti-Israel politics is on track to become mayor of the largest city in America, which has the largest Jewish population outside of Israel. Coupled with Democrats’ reluctance to offer support for President Donald Trump’s targeted strikes on Iranian nuclear sites, which drew support from major Jewish groups, Mamdani’s ascension has some pro-Israel Democrats concerned about the future of their party.

Put more bluntly by another senior Biden administration official: “I feel like a person without a party,” they told Jewish Insider.

Those two voices, who served at high levels of the Biden White House, are part of a small cadre of disillusioned former Biden staffers who want to see a more vocally pro-Israel tack from the Democratic Party’s current leaders, although they aren’t yet willing to say so publicly with their names attached. But their frustration represents a simmering undercurrent of concern among Jewish Democrats that has started to spill into the open after Mamdani’s victory.

Lawrence Summers, an economist who served as treasury secretary under President Bill Clinton and director of the National Economic Council under President Barack Obama, said in a post on X that he is “profoundly alarmed” about the future of the Democratic Party and the country “by yesterday’s NYC anointment of a candidate who failed to disavow a ‘globalize the intifada’ slogan and advocated Trotskyite economic policies.”

Some prominent Jewish Democrats acknowledged Mamdani’s shortcomings but tempered that concern by noting that voters were likely drawn in by his economic messaging, not his anti-Israel stance, and by the presence of a scandal-plagued rival in Andrew Cuomo, who ran a lackluster campaign.

“I think it is very disheartening that he was not able to say the phrase ‘globalize the intifada’ feels very threatening to Jews. I find that very distressing, but I don’t think that that’s the issue that the majority of New Yorkers were voting on,” said former Rep. Kathy Manning (D-NC), the board chair of Democratic Majority for Israel. “I don’t see it as a referendum on, people don’t care about antisemitism.”

Halie Soifer, CEO of the Jewish Democratic Council of America, expressed concern that New York Democrats elected a candidate “whose views on Israel deeply concern many American Jews.” But, she argued, “Democratic leadership and the vast majority of our elected officials stand with Jewish Americans on the range of issues of importance to Jewish voters.”

Mamdani’s election came days after a watershed foreign policy moment, in which Trump ordered American strikes on several Iranian nuclear sites. Democrats, even many moderates, responded by criticizing Trump for his unilateral action without consulting Congress, with many — including House Minority Leader Hakeem Jeffries (D-NY) — failing to even acknowledge the threat Iran posed to Israel and the U.S.

“I think overwhelmingly, Democrats have not done a good job, and the proof is in the pudding, that even staunch Democrats who would never consider supporting Donald Trump or ever vote for a Republican are just really pained by what feels like a refusal to even acknowledge the seriousness of the threat of the Iranian nuclear program,” said Amanda Berman, CEO of Zioness, a progressive pro-Israel organization. Manning said she “would have loved to see not just my [former] colleagues but newscasters acknowledge that Iran is a bad actor.”

Wary Jewish Democrats are keeping a watchful eye on how party leaders handle Israel- and antisemitism-related issues.

“While I believe the majority of Democrats are pro-Israel economic moderates, we will see if our party leadership capitulates to the party’s most radical anti-Israel wing in the city with the most Jews in the world,” Esther Panitch, a Democratic state representative in Georgia and the only Jewish politician in the Georgia Statehouse, told JI on Wednesday. “I’m not optimistic at this moment, given that they have welcomed non-Democrats DSA [Democratic Socialists of America] and WFP [Working Families Party] into the tent.”

Senate Minority Leader Chuck Schumer and Jeffries, both of whom live in New York City, each congratulated Mamdani with social media posts on Wednesday, although they did not outright endorse him.

Sara Forman, the executive director of New York Solidarity Network, which promotes pro-Israel candidates in local races in New York, called Mamdani’s election “a seismic change” for Democratic politics in New York.  Far-left activists, she said, are now firmly inside of the party apparatus in the city, and she pledged to stick around and work to make sure the party is not represented by those activists.

“I am not advocating Jews leaving the Democratic Party,” Forman told JI. “One of the things that I’m going to work on, and I’ve been working on, is getting people to join me in the chorus and to not sit back and watch the car accident happening in front of their eyes, but instead, speak up. Speak out. Don’t surrender.”

According to Bradley Tusk, a venture capitalist and longtime Democratic operative who served as former New York City Mayor Michael Bloomberg’s 2009 campaign director, the challenge for Democrats is how to overcome the most ideological voters who turn out to vote in primaries.

“It wasn’t that he was this candidate who had all these interesting, exciting affordability ideas, but also happened to be anti-Israel. The anti-Israel was a big part of what allowed him to succeed,” Tusk told JI. “I think structurally, we have put ourselves in a bind where, when the Democratic Party is only decided by small ideological actors who vote in primaries, and that group tends to lean much more into anti-Israel, antisemitism, the Democratic Party is pretty stuck.”