The House minority leader, Hakeem Jeffries, endorsed Zohran Mamdani for New York City mayor on Friday, ending a four-month standoff that left the Democratic nominee without the backing of one of the party’s most powerful figures until the day before early voting begins. The announcement arrives after months of pressure from progressives in Congress and after the top Democrat has been repeatedly grilled by reporters about his reluctance to support his party’s candidate. “Zohran Mamdani has relentlessly focused on addressing the affordability crisis and explicitly committed to being a mayor for all New Yorkers, including those who do not support...