NEW YORK - When Zohran Mamdani takes office on Jan 1 as New York City’s mayor, he will inherit a role that’s described as the second-hardest job in America. He will be responsible for the city’s nearly 8.5 million residents and serve as chief executive of the single largest employer in New York, overseeing a municipal workforce of nearly 300,000 permanent employees, as well as 72 city agencies and more than 200 different boards and commissions. But Mr Mamdani, a 34-year-old democratic socialist who rose from obscurity in a few short months to win the mayoral election in November, faces...