Brad Lander, the outgoing comptroller of New York City, announced Wednesday that he is running for Congress, challenging U.S. Rep. Dan Goldman in a Democratic primary for a liberal district in lower Manhattan and northwest Brooklyn.

Lander, a progressive ally of Mayor-elect Zohran Mamdani, launched his campaign in a video and social media posts, promising to offer “courageous leadership in the face of Donald Trump’s attacks on New Yorkers.”

“At a moment of dark oppression, we can shine by fighting back together,” he said. “While the oligarchy drives an affordability crisis, they shouldn’t be able to buy a seat in Congress. While our immigrant neighbors are being demonized and attacked, we can put our bodies on the line to protect them,” Lander noted in the video.

He also evoked the late children’s TV host Fred Rogers in his announcement video, singing “Would you be mine? Could you be mine? Won’t you be my neighbor?”

“I know it’s corny, but I love the idea that democracy is just neighbors working together to make our lives in common better,” he added, revealing the grassroots philosophy behind his campaign.

Lander has been eyeing a challenge to Goldman since he lost the Democratic mayoral primary to Mamdani this summer. Mamdani praised Lander’s unwavering principles and deep knowledge in his endorsement.

Both candidates have been vocal critics of the federal government’s deportation agenda and have actively participated in immigration court observations over recent months. Lander's activism includes two arrests related to immigration issues and facing a misdemeanor obstruction charge from one incident.

Vermont Sen. Bernie Sanders also endorsed Lander, highlighting his commitment as a 'relentless fighter for working people.' As Lander prepares for his campaign, he will leave his office as comptroller next year, opting not to seek reelection.

Goldman, a two-term congressman and heir to the Levi Strauss fortune, is viewed as a moderate Democrat, known for his previous role as lead counsel in Trump's first impeachment. An email seeking comment was sent to his campaign office.

Lander and Mamdani previously endorsed each other in the mayoral primary, showcasing the strategic alliances formed to counteract their past opponents.