They have given these schools everything they said was needed to increase performance, black teachers, principals, school boards, etc. They twisted a formerly working institution into a menagerie of violence, ignorance, and excuses. They refuse to take any responsibility or even acknowledge the community culture might be the problem. Order, Discipline, and high expectations are the only things that have been PROVEN to work in these school systems.
It has NEVER been proven, because it cannot be proven, that universal compulsory academic education to age 18 can work.
You can have all the high expectations you want, but when you populate an Algebra II or English Lit class at the high school level with a group whose IQs range from 70-95, with a MEDIAN of 83-85, you have a formula for failure.
What form the failure takes varies by gender, and by the formulae used for order and for discipline. However, a very substantial fraction of the males held against their will in these urban "school" systems cannot be disciplined even in State Prison, so I am skeptical that better teachers or less powerful teacher unions can do the trick.
Face the truth. The experiment is a failure.