It’s just after sunset on Halloween evening in the Brooklyn neighborhood of Park Slope, and Zohran Mamdani is booking it up Seventh Avenue as if he were a costumed eight-year-old who’d just heard there was a house giving out full-sized candy bars a few blocks away.
The 34-year-old Democratic mayoral candidate—dressed in his usual non-costume of a navy suit and dark striped tie—is surrounded by his aides, two security guards, and hundreds of shrieking, delighted onlookers. He gamely…

