To some degree, almost everyone by now and in the foreseeable future, has some hereditary relations to a slave.
If then, how does the the government even determine the requirements on how much one needs to become a 'descendant' of a slave?
If it is some kind of numerical value, then that will probably 80% of Americans. Very hard to handle.
Affirmative Actions is the closest thing to 'reparation' and that also have been challenge on its fairness.