Professor Buchanan saw the tendency of people to self-segregate as problematic. James Buchanan was a free-market oriented economist, compared to other economists, but he was not doctrinaire. Dr. Buchanan was open to a few types of state intervention, and he did see racial segregation as problematic. Did Dr. Buchanan agree with all of the policies people on the political left have proposed for desegregation? Most certainly not, but he clearly opposed segregation, and would at least consider integration policies.
Source