Zohran Mamdani became mayor of New York City on Thursday, taking over one of the most unrelenting jobs in American politics with a promise to transform government on behalf of the city's striving, struggling working class. Mamdani, a Democrat, was sworn in at a decommissioned subway station below City Hall just after midnight, placing his hand on a Quran as he took his oath as the city's first Muslim mayor. After working part of the night in his new office, Mamdani then returned to City Hall in a taxi cab around midday Thursday for a grander public inauguration where U.S. Sen. Bernie Sanders, one of the mayor's political heroes, administered the oath for a second time. Beginning today, we will govern expansively and audaciously. We may not always succeed, but never will we be accused of lacking the courage to try, Mamdani told a cheering crowd. To those who insist that the era of big government is over, hear me when I say this: No longer will City Hall hesitate to use its power to