Recently appointed Mamdani official abruptly resigns as antisemitic tweets unearthed

Josephine Stratman, New York Daily News on Dec 18, 2025

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A top official in Mayor-elect Zohran Mamdani’s incoming administration resigned abruptly Thursday after a series of anti-Jewish tweets were uncovered, just one day after her appointment was announced.

Cat Da Costa, who would have served as Mamdani’s head of appointments in the mayor’s office, resigned hours after the social media posts were unearthed. She would have been tasked with screening top hires for his administration.

“I spoke with the Mayor-elect this afternoon, apologized, and expressed my deep regret for my past statements,” Da Costa said in a statement.

In tweets from 2011 and 2012, per screenshots shared by the Anti-Defamation League, Da Costa, who’s now 33, complained about “money hungry Jews” and wrote that “Far Rockaway train is the Jew train.”

Da Costa, who is married to a Jewish man, apologized for the hateful missives.

“These statements are not indicative of who I am. As the mother of Jewish children, I feel a profound sense of sadness and remorse at the harm these words have caused,” she said. “As this has become a distraction from the work at hand, I have offered my resignation.”

While her resignation brought the chapter to a swift conclusion, the De Costa situation raises questions about the Mamdani transition team’s vetting of job candidates. Da Costa’s appointment Wednesday came after a month-long pause in appointments from Mamdani.

Dora Pekec, a spokesperson for the transition, said the transition had no knowledge of the past tweets, though they were publicly available until the account was apparently deleted Thursday afternoon.

“Catherine expressed her deep remorse over her past statements and tendered her resignation, and I accepted,” Mamdani said.

Just a day earlier, in announcing her appointment Wednesday, Mamdani called Da Costa “a true expert in talent acquisition, making sure excellence is at the core of city government operations.” She previously also worked in Mayor de Blasio’s administration.

The issue also touches on a problematic issue for Mamdani. The pro-Palestine mayor-elect’s stance on Israel, such as boycotting the country or the controversial phrase “globalize the intifada,” have sparked criticism that Mamdani’s positions promote anti-semitism. The ADL has launched a Mamdani “anti-semitism tracker.”

Da Costa’s husband came to his wife’s defense on Thursday afternoon.

“I don’t come back to this awful place much these days but as the Jew who married Cat, I can guarantee she has grown so much since some dumb tweets when she was 19,” Ricky Da Costa, who works as a deputy comptroller, wrote.

“Her remorse, like everything else about her, is deeply genuine & she works so hard for a NYC where everyone is safe.”

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(With Chris Sommerfeldt.)

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