Zohran Mamdani, who won attention for a series of online campaign videos, is the first candidate to air a broadcast ad in the Democratic primary race.

© Andres Kudacki for The New York Times

Former Gov. Andrew Cuomo is embracing a so-called Rose Garden strategy in his tightly controlled campaign for mayor of New York City.

© Shuran Huang for The New York Times

Ms. Adams, the City Council speaker, won endorsements from Letitia James, the state attorney general, and from three major unions including District Council 37.

© Todd Heisler/The New York Times