To measure judicial diversity over time, researchers collected data on each president's judicial appointments and compared those judges to the judges they had replaced. When a white male judge was replaced by a woman or a man of color, diversity increased by one point. When a white male judge was replaced by a Black female judge, diversity increased by two points. The math works the same way in reverse. The data shows that Donald Trump is the only president in 40 years to actually make the federal judiciary less diverse.