President Trump sees himself as the antithesis of President Obama, and that’s true in ways large and small. Both men, however, share a fondness for the identity politics that continue to poison U.S. race relations.

If you were shocked that President Trump had to be pressured into condemning by name neo-Nazis, Klansmen and white supremacists, then you probably haven’t been paying enough attention. His Saturday remarks on Charlottesville, Va., where protesters clashed violently over a statue in a park of Confederate Gen. Robert...