The post Civil War failure to eradicate the power of the secessionists who subsequently retook…
Vinson Ryan Nash

Not a bad answer, but there is a much simpler one available; more of society had a problem with segregated schools in 1954 than in 1896.

Likewise, nobody is going to do anything about racially motivated executions-by-law-enforcement, or write any policy to hinder it, until a sufficient portion of society has a problem with it -that is, until we actually believe that it is a bad thing in general. We do not. We are moving in that direction, but I wouldn’t say we are there.