Before Trump took office, conventional wisdom was that American blacks would never vote Republican. As Lyndon Johnson reputedly said after passing the Civil Rights Act, “I’ll have those n****** voting Democratic for the next 200 years.†It didn’t matter that Democrats broke their promises or that their policies worsened the plight of inner-city blacks. Black voters remained loyal. This year, though, after Trump spent four years making a positive difference for black America, blacks are breaking ranks and openly supporting President Trump. Thomas Sowell wrote in 2016, shortly before Trump was elected, “Black votes matter. If Republicans could get...