As good an analysis as I have seen
Americans are segregating by income more than ever before. Forty years ago, most cities (including Detroit) had a mixture of wealthy, middle-class, and poor residents. Now, each income group tends to lives separately, in its own city — with its own tax bases and philanthropies that support, at one extreme, excellent schools, resplendent parks, rapid-response security, efficient transportation, and other first-rate services; or, at the opposite extreme, terrible schools, dilapidated parks, high crime, and third-rate services.
The geo-political divide has become so palpable that being wealthy in America today means not having to come across anyone who isn’t.