New York City is the center of Democratic establishment power. The leaders of both the House and Senate Democrats are from there, oodles of party money are raised there and many of the consultants, public relations flacks and pollsters who work for top candidates live there. This cycle, though, it’s also going to be the center of a Democratic insurgency. Following the triumph of progressive Assembly member Zohran Mamdani in New York City’s mayoral race, a slew of incumbent House Democrats