My understanding is that Detroit MI (for a worst case example) during it's heyday of the 1950's had a good to excellent public school system. By 1980, the school system was considered one of the worst in the country and middle class blacks had started to follow middle class whites into the suburbs. Detroit will not become a city people want to live in again until the school system becomes one that people want to send their children to.
When was the last time you heard any tales of some parent committing fraud to get their kid into an urban school district?
Yep. Count me among them. The HS in my (former, urban) district was very proud of the fact that they'd raised - RAISED, mind you - their graduation rate to 56%. Never mind the drugs, crime, and the fact that the 56% figure likely took "graduate" at its most liberal meaning.
Unimaginable. We moved to a nice rural, conservative area before the kids got tossed into that system. Homeschooling is still a backup option, but we have great local schools that we're planning on taking advantage of. Why anyone would raise their kids in an urban armpit, is beyond me.