This review is a gross distortion of what libertarians believe--particularly about segregation. Nor is there any support that Buchanan himself supported segregation. To the contrary, evidence shows he opposed it. http://philmagness.com/?p=2185 
https://www.washingtonpost.com/news/volokh-conspiracy/wp/2017/09/01/georg-vanberg-democracy-in-chains-and-james-m-buchanan-on-school-integration/?utm_term=.fe5f7a4834b3