William:

… the decentralized republicanism advocated by Jefferson ….

You forgot to add an important qualifier. What you no doubt meant to say was “the decentralized republicanism advocated for white people by Jefferson.”

The system of rule that Jefferson advocated, and personally instituted, for black people, was not “decentralized republicanism,” but rather hereditary, personal, absolutist tyranny–tyranny of a form almost unparalleled in human history for its invasiveness, immiseration, and ruthless brutality against its unwilling subjects.