He's right. As a matter of fact, this reverse migration is already happening. Black folk can either be the dominant group and control state and local politics, or stay in the rainbow coalition and beg other groups for consideration of our issues.
The South can be transformed if enough of us act with vision and purpose. NC, SC, LA, AL, MS, VA, MD, DE, and ARK can give a sizable amount of control on the federal level through Black governors, Senators, and Congressional reps. 16 potential Senators and several dozen Congressional reps can force votes on issues pertinent to Black people.