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

New York City Mayor-elect Zohran Mamdani’s administration faced an early setback Thursday as appointee Catherine Almonte Da Costa resigned following the discovery of antisemitic social media posts she made over a decade ago.

Da Costa, who had been selected to lead Mamdani’s office of appointments and handle talent recruitment strategy, stepped down after the Anti-Defamation League (ADL) shared posts from 2011 and 2012 that the Jewish advocacy organization said “echo classic antisemitic tropes and otherwise demean Jewish people.”

“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 in a statement released by Mamdani’s office.

Mamdani confirmed accepting Da Costa’s resignation, saying, “Catherine expressed her deep remorse over her past statements and tendered her resignation, and I accepted.”

The incident marks an early challenge for Mamdani’s incoming administration, which has already faced scrutiny over the mayor-elect’s positions on Israel. Following Mamdani’s November election victory, the ADL announced a new monitoring tool specifically designed to track policies and personnel hired by the incoming mayor, who has been a vocal critic of Israel’s actions.

Da Costa’s professional background includes previous experience in the mayor’s office over a decade ago, followed by roles at a private communications firm and the prestigious auction house Sotheby’s. Her appointment had been announced just days before her resignation.

The controversy comes amid heightened tensions and increased scrutiny of antisemitism in public discourse, particularly in New York City, home to the largest Jewish population outside of Israel. Political figures’ stances on Israel and Palestine have become increasingly contentious points in local politics, especially following the ongoing conflict in Gaza.

Mamdani, who takes office next month, has faced pressure throughout his campaign and transition to demonstrate that his opposition to Israel’s military actions in Gaza does not equate to antisemitism. During his campaign, he drew criticism for refusing to condemn the phrase “globalize the intifada,” though he has recently indicated he discourages its use.

The ADL declined to comment following Da Costa’s resignation. The organization has been increasingly active in monitoring political discourse around Israel and antisemitism, particularly in major urban centers where debates about the Middle East conflict have intensified.

This resignation highlights the challenges facing progressive politicians who criticize Israeli policies while attempting to navigate accusations of antisemitism. For Mamdani, who will be leading a city with significant Jewish and Muslim populations, balancing these sensitivities will likely remain a continuing challenge throughout his administration.

The incident also underscores the growing role of social media history in political appointments, with comments made a decade earlier still carrying consequences for public officials today. Da Costa’s situation reflects the permanent nature of digital footprints and their potential to impact careers long after posts are made.

As Mamdani prepares to take office, the resignation serves as an early test of his administration’s vetting processes and its ability to handle controversies related to one of the most sensitive political topics in New York City politics. The mayor-elect now faces the task of finding a replacement for this key appointment while maintaining focus on his transition priorities ahead of his January inauguration.