Three candidates endorsed by Zohran Mamdani swept to victory in Democratic congressional primaries on Tuesday, showing that the coalition which powered the New York City mayor to a surprising victory last year is gaining strength.

Some of the city’s most established political figures were toppled in races that highlighted divisions within the party over ideology, Israel and immigration.

Former New York City comptroller Brad Lander defeated two-term Congressman Dan Goldman in New York’s 10th Congressional district, while New York state lawmaker Claire Valdez won in the 7th district in Queens and Brooklyn. Darializa Avila Chevalier, a community organiser and graduate student, defeated incumbent Adriano Espaillat in the Democratic primary in the 13th Congressional District.

Tuesday’s Congressional primaries were viewed as a test of the political strength of Mamdani, who has been in office less than a year but is already trying to reshape New York’s Democratic power structures. In stepping in to key races to back candidates who shared his views, he strained ties with other long-standing Democratic leaders.

It was a gamble that appears to have paid off. The mayor’s victories on Tuesday seem certain to further unsettle his opponents, including wealthy residents of the city who have recoiled at his tax policies and some Jewish voters who have been angered by his outspoken criticism of Israel.

The victories for Valdez and Avila Chevalier were the latest gains for the Democratic Socialists of America, who have drawn increasing political power from voter discontent about rising rents, costly childcare and stagnant wages.