Yes, I actually do know quite a bit about that stuff. Detroit hasn't had a Republican government in over 60 years. Of that just over 40 were Black mayors and major portions or majority Black city councils. Detroit's decline, like it or not, started in the 70's concurrent with the election of a Black government to run the city.
I won't suggest that alone was the cause, it certainly wasn't, but it is likely to have not helped in the least. Call it racist if you want, but it is historically accurate and that doesn't make it racist, it makes it factual. Just because you don't like those facts doesn't change them.