Two key primaries in New York City delivered whopping victories for an emboldened left led by Mayor Zohran Mamdani on Tuesday, as democratic socialists sought to define the future of the Democratic Party.

Mamdani-backed congressional candidates Claire Valdez and Brad Lander were declared the winners in their two districts less than half an hour after polls closed. While democratic socialist challenger Darializa Avila Chevalier was still neck-and-neck with fifth-term incumbent Rep. Adriano Espaillat, one message from the night was clear: The left isn’t just having a moment — it’s dictating how Democrats play the game of electoral politics.

“Even when we are outspent, our agenda and operation bring out voters in a way the Democratic Party establishment no longer aspires to,” Gustavo Gordillo, co-chair of the New York City chapter of the Democratic Socialists of America, told The Intercept. “It is democratic socialists who are defining much of the political terrain in New York.”

Several races played out as proxy wars between the Democratic Party establishment and progressive insurgents, or even between progressives and socialists, to prove who would do more to disrupt the status quo. In hotly contested primaries spanning four out of five NYC boroughs, candidates touted endorsements from Mamdani and Sen. Bernie Sanders, I-Vt., as well as their proximity to the most unconventional wings of the Democratic Party.