On Sunday night in Queens, the vibrations from thousands of cheering Zohran Mamdani supporters reverberated throughout Forest Hills Stadium, as the audience burst into the same chant as speaker after speaker took the stage: “DSA, DSA.” Mamdani’s surge past former Gov. Andrew Cuomo in June’s Democratic primary for New York City mayor didn’t just put the 34-year-old state assemblyman on the political map. It also highlighted the Democratic Socialists of America, or DSA — a spotlight that's