New York's congressional candidates campaigned on Monday, the last full day before the primary election scheduled for Tuesday. Mayor Zohran Mamdani promoted three House candidates through campaign videos and a rally with U.S. Sen. Bernie Sanders.

Jack Schlossberg, a candidate for Congress representing part of Manhattan and the grandson of former President John F. Kennedy, rallied with David Letterman during his campaign. Caroline Kennedy recorded a campaign advertisement for Schlossberg.

Alex Bores, a state Assembly member and a candidate in the same Manhattan race, released an advertisement regarding artificial intelligence. Micah Lasher and George Conway are also candidates in that congressional race. Mayor Mamdani has not made an endorsement in the race involving Schlossberg, Bores, Lasher, and Conway.

Darializa Avila Chevalier is challenging U.S. Rep. Adriano Espaillat in a primary election. Espaillat's district includes northern Manhattan and part of the Bronx; he was the first Dominican American elected to Congress. Chevalier stated in a recent debate that she regretted inflammatory social media posts she made in her 20s and apologized for a post about former Vice President Kamala Harris.

Brad Lander is challenging U.S. Rep. Dan Goldman in another primary election. Lander received Mayor Mamdani's endorsement and attended a ceremony at City Hall celebrating the Knicks' NBA championship win on Thursday.

Claire Valdez is challenging Brooklyn Borough President Antonio Reynoso in a primary election to succeed retiring U.S. Rep. Nydia Velazquez. Mayor Mamdani is supporting Valdez's campaign. "The party of the past will not be what leads us into the future. We need a Democratic Party with backbone," Mamdani said.