Your first statement is an attempt to demonstrate moral superiority and therefore merits no response. Your second statement is misleading, in that it sweeps under the rug how Detroit's descent into poverty mirrored its changing demographics.

You could, of course, attempt to disprove Daniel_Newby's contention that demographics is at the bottom of this. All that you need to do is provide a single counterexample by pointing out an instance--just one will suffice for our purposes--of a city that became richer or that economically speaking at least held its own even as the percentage of blacks comprising its population grew. This seems like a simple enough task.

I remember reading several articles about massive "white plight" in Detroit. Especially in the middle class.

1950 - 16% black 2000 - 81% black http://historydetroit.com/statistics/

You really believe that? Congratulations, you have identified the greatest market development opportunity ever. Simply recruit a million Africans who are being kept down by racists like me, teach them to be engineers, and retire a billionaire on the recruiting commissions.

Detroit used to be prosperous because blue collar Caucasians and Africans are damn valuable in a world without robots. Now they are cognitively obsolete.

P.S. Bill Gates decided that the problem was that not everybody in our world of shameful inequalities could get a world-class university prep education. He paid out of his own pocket to make the pilot project happen. The result was ... almost no improvement.