"... cumulative results of the discrimination that confined black Americans to ghettos in the first place."
Hogwash. The blacks "confined to ghettos" are there by their own choice. There are gazillions of "Affirmative Action" programs and scholarships for any black who wants to get an education and get into the American mainstream.
Thank you for pointing that out. In his book "Bad Students, Not Bad Schools" Robert Weissberg exposed the lie of black inner city students chained to poor schools unable to escape.
Weissberg mentioned the programs set up for many of those kids who want to get out. A very large pct. of those kids and parents don't want to leave their ghetto schools. They're happy where they are. And THEY'RE!!! the ones who make the schools awful. Even well-meaning conservatives get that twisted.
It's not bad schools because of bad teachers (although that might be the case in many of them.) It's mostly impossible to teach those kids in the chaotic environment the kids create. Good teachers are frustrated by trying reach unreachable, semi or wholly violent, out of control children.