It’s not unusual to hear chants of “U-S-A” at a political event. But the chant that rang repeatedly around Williamsburg’s 99 Scott Studio after last night’s near-total sweep by socialist candidates was off by one letter: “D-S-A.”

The acronym refers to the Democratic Socialists of America, whose New York chapter, NYC-DSA, emerged as the major winner in last night’s primary elections in New York: all but one of its nine endorsed insurgent candidates won their races for US Congress and New York’s state legislature. Diana Moreno was also reelected to her state assembly seat after winning it in a special election last year, and outside the city, Buffalo DSA’s Adam Bojak was elected to the assembly for the first time. (In Syracuse, DSA-endorsed challenger Maurice Brown is leading his assembly race, but it is still too close to call.) They did so on the back of a furious, sweat-drenched door-knocking operation that has, a year after a similar grassroots effort catapulted another member, Zohran Mamdani, into the New York mayor’s office, firmly established the group as a formidable political force — one that bested unions and even the Working Families Party (WFP), for decades the leading progressive electoral power in the city.

Even in their disbelief at how quickly and decisively the results had gone their way, the hundreds of rapturous DSA members who packed into the now–Democratic nominee for New York’s Seventh Congressional District Claire Valdez’s official watch party were keenly aware of their newfound power.