In 2019, it seemed to many that Gov. Ralph Northam’s career was over. That year, the Democratic governor of Virginia became embroiled in a highly publicized blackface scandal centered on a racist picture in his medical-school yearbook. There were widespread calls for his resignation. Two years later, Mr. Northam has emerged as the most racially progressive leader in the state’s history. How did it happen? Guest: Astead W. Herndon, a national political reporter for The New York Times.