New group forms to challenge Mamdani with ads and lawsuits

A new anti-Mamdani operation has taken shape with a war chest, a lawyer at the helm and litigation already in its playbook. NYC Common Sense, a nonprofit registered in Delaware, has raised more than $1 million and plans to attack Mayor Zohran Mamdani with digital ads, policy papers and lawsuits aimed at his administration.

Jim Walden, who ran an unsuccessful independent campaign for mayor last year, is chairing the group. Phil Singer, the political consultant and founder and chief executive of Marathon Strategies, is a founding member. Marathon Strategies previously worked on a $30 million super PAC that backed former Gov. Andrew M. Cuomo in the same race, underscoring how closely the city’s donor class has kept its political machinery organized around Mamdani’s rise.

The group is being built as an opening move to constrain Mamdani before his agenda is fully in place. Walden and Singer said their concerns focus on traffic enforcement, homelessness and Mamdani’s decision not to expand a rental assistance voucher program as a cost-cutting measure. Walden said the effort would not center on Mamdani’s support for Palestinians and criticism of Israel, even as that issue has driven criticism from some politically connected opponents. In a recent interview, Walden described Mamdani as an “incredibly ideological” mayor whose policies may be borrowed from studies in cities unlike New York and then applied in a fiscally undisciplined way.

The formation of NYC Common Sense fits into a broader escalation in New York City politics, where money has become one of the main tools of resistance to Mamdani’s administration. Earlier in the race, business groups and other opponents raised large sums, and New Yorkers for a Better Future Mayor 25 was reported ready to spend $20 million to defeat him. A pro-Mamdani super PAC, OneNYC, formed in the same period, turning the mayoral contest into a costly fight over the city’s political and economic direction.

That spending battle reflected deeper concerns among Wall Street figures and major donors about what Mamdani’s victory would mean for policing, business confidence and the city’s governing philosophy. Gov. Kathy Hochul said she had concerns about policing and the business climate and would work with whoever prevailed. With NYC Common Sense now preparing ads, legal challenges and policy attacks, the opposition to Mamdani is moving from private alarm to a coordinated campaign designed to box him in before his agenda can harden into policy.