Brad Lander, the New York City comptroller, is actively weighing a challenge to Rep. Dan Goldman (D-NY) in next year’s primary election, according to people familiar with the matter, raising the prospect of a competitive race between an ally of far-left Democratic mayoral nominee Zohran Mamdani and a pro-Israel incumbent.

Lander had, until recently, been widely expected to land a top job in a potential Mamdani administration, with whom he cross-endorsed during the June primary.

But following reports of an emerging strain in their alliance, Lander, a 56-year-old Jewish Democrat, is more closely eyeing Goldman’s seat, which covers Lower Manhattan and a section of Brooklyn that includes the progressive enclave of Park Slope. Lander’s thinking was reported on Monday by City & State New York, which said that he had told allies he was planning a primary challenge to Goldman.

Political strategists predicted that Lander, a longtime resident of Park Slope who represented parts of the district as a city councilman, would be a formidable candidate, particularly if Mamdani wins the mayoral race. “The polling and voter data would indicate a progressive running in this district would have a strong chance,” Chris Coffey, a Democratic consultant who resides in the district, told Jewish Insider on Monday.

“Dan will presumably have money and he’s the incumbent,” Coffey said of Goldman, an heir to the Levi Strauss fortune whose estimated net worth is up to $250 million. “But the mayor’s race will hang over this race.”

A primary matchup between Lander and Goldman would serve as a test of the Democratic electorate’s support for mainstream pro-Israel representation in New York City, as Mamdani’s campaign has brought renewed energy to the activist left opposed to Israel’s war in Gaza and lawmakers’ continued support for the Jewish state.

Goldman, a Jewish Democrat, has faced some backlash from constituents in his overwhelmingly left-leaning district over his support for Israel and continued refusal to endorse Mamdani, who is the front-runner in next Tuesday’s mayoral race. 

The 49-year-old congressman said in an interview last week that he remains “very concerned about some of the rhetoric coming from” Mamdani with regard to Israel. Goldman told CNN he had asked Mamdani, who has long been a fierce critic of Israel, to speak out against rising anti-Israel violence, but “I frankly haven’t really seen him do much on that.”

The potential race would also set up a unique clash between two Democrats who identify as Zionists but have differing views on what the term means. While Lander has been a vocal critic of Israel’s war in Gaza and called for pulling aid to Israel, Goldman, for his part, has been a defender of Israel during his tenure in office — even as he has not hesitated to challenge the Israeli government on key issues.

A spokesperson for Lander told JI on Monday that he is now “focused on electing Zohran Mamdani as mayor of New York City,” but did not comment on a challenge to Goldman.

Lander, speaking at a rally for Mamdani’s campaign on Sunday evening, made comments about electing progressives that some political observers viewed as a possible hint at his own plans to run for Goldman’s seat next year.

“We’ll take that fight to the halls of Congress, where it’s more important than ever that we have leaders who understand this moment and will be partners to Zohran,” said the outgoing one-term comptroller.

Goldman’s team, which recently dismissed a poll showing that he would lose in a primary opposing Lander, did not respond to a request for comment. 

In a statement on Monday, Goldman weighed in on a new lawsuit challenging a House district covering Staten Island and parts of southern Brooklyn, which if successful could reshape the congressional map in New York. The seat, held by Rep. Nicole Malliotakis (R-NY), borders Goldman’s district.

“NY-10 is my home and I will be running for Congress in my home district,” Goldman said in his statement. “If Staten Island is drawn into my district, then I will be ready to step up and take the fight for democracy and a Democratic House majority to Nicole Malliotakis’ doorstep. Nothing can stand in the way of us defeating Donald Trump and his spineless lackeys in Congress. Flipping the House isn’t optional — our future depends on it.”

If Lander chooses to run, he would likely have some company on the left in the primary, as Alexa Avilés, a city councilwoman who is closely aligned with the Democratic Socialists of America, is also reportedly exploring a bid, threatening to split the progressive vote.

One Democratic insider said that Lander had, as of last week, been informing allies he was going to join a likely future Mamdani administration. “Maybe he is floating his name to keep options open and Alexa out,” the insider speculated to JI on Monday.

In addition to Avilés, Yuh-Line Niou, a far-left former state assemblywoman, is also considering a primary challenge to Goldman, people familiar with the matter told JI. Goldman narrowly defeated Niou in a crowded primary in 2022, when he was first elected to the House. 

Niou did not respond to a request for comment on Monday. 

Even as he has drawn criticism from some left-wing voters, Goldman still maintains solid support in one of the more heavily Jewish congressional districts in the country, according to Ramon Maislen, a Jewish community activist in Park Slope.

“Many progressive and moderate Democrats will happily line up behind Dan,” Maislen told JI.