The great jazz musician Miles Davis was known for his boorishness, especially toward his white fan base. Davis would play his trumpet with his back to the audience and curse at people between sets. “If somebody told me I only had one hour to live, I’d spend it choking a white man,” he once told a newspaper reporter. “I’d do it nice and slow.” His admirers ate it up.

Reading Ta-Nehisi Coates’s new essay on Donald Trump in the Atlantic magazine brought Davis to mind. Mr. Coates, who couldn’t be more highly regarded among the...