America’s largest city is run by Zohran Mamdani, a card-carrying member of the Democratic Socialists of America. Los Angeles, the second-largest metro, could follow: Fellow DSA member Nithya Raman seems poised to become its next mayor. A new California Post poll shows her leading Mayor Karen Bass. If Raman wins, DSA members will hold both mayors’ offices, forcing Democratic Party leaders to ask whether they still run their party, or whether they…