Well, I can speak for DC. It has become more white as previous bad parts of town have been gentrified. Mostly because the local leadership (after that crackhead Barry) understood that they needed to encourage development, not punish it. So there are many neighborhoods that within the last 10 years have changed into nice neighborhoods. Now the trick would be to somehow change the school system because as kids reach school age.
Naw, the elite sends their kids to fancy private schools. The remaining Whites? Many of them are homosexual and therefore do not have kids. Others are liberal and they tend not to reproduce either.
Productive black families are increasingly leaving the city for greener pastures elsewhere.