Mamdani appointee resigns after her decade-old antisemitic social media posts resurface

New York City Mayor-elect Zohran Mamdani listens as U.S. President Donald Trump speaks in the Oval Office of the White House, Friday, Nov. 21, 2025, in Washington. (AP Photo/Evan Vucci)

NEW YORK — One of New York City Mayor-elect Zohran Mamdani’s appointees has resigned over social media posts she made more than a decade ago that featured antisemitic tropes, Mamdani’s office said Thursday.

In a statement, Catherine Almonte Da Costa, who was tapped this week to join the incoming administration, said she expressed “deep regret” for the posts, which date back to 2011 and 2012 and were recently shared online by the Anti-Defamation League.

“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,” Da Costa said.

She had been selected to lead Mamdani’s office of appointments, handling “talent recruitment strategy.” Da Costa worked in the office more than a decade ago and more recently held roles at a private communications firm and at Sotheby’s, the mayor-elect’s office said.

Mamdani has accepted her resignation, his spokesperson confirmed.

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

The Anti-Defamation League declined to comment after Da Costa’s resignation. The prominent Jewish advocacy organization had shared three tweets from Da Costa that it said “echo classic antisemitic tropes and otherwise demean Jewish people.”

Following Mamdani’s election in November, the group announced a new tool “to track and monitor policies and personnel” hired by Mamdani, who has been heavily critical of Israel.

Mamdani, who takes office next month, has been under intense pressure to show that his opposition of Israel’s military actions in Gaza do not amount to antisemitism. During his campaign, Mamdani drew criticism for refusing to condemn the phrase “globalize the intifada,” though he has more recently said he discourages people from using it.

The Associated Press