Riots cause cities to become more leftist as swing voters run for the hills and beyond where they then tend to vote more conservatively. Nothing generates new Republicans faster than Democrats rioting and looting.
There are a number of effects at play though.
1960: Macomb 63-37 D, Oakland 54-45 R, Washtenaw 61-39 R
1964: Macomb 75-25 D, Oakland 61-38 D, Washtenaw 62-38 D
1968: Macomb 55-30 D, Oakland 45-45 R, Washtenaw 47-43 R
1972: Macomb 63-35 R, Oakland 64-34 R, Washtenaw 52-47 D
1976: Macomb 51-47 R, Oakland 59-40 R, Washtenaw 51-46 R
2016: Macomb 54-42 R, Oakland 51-43 D, Washtenaw 68-27 D
It appears U of M started tilting left around 1972, and has gotten worse ever since. The Kennedy assassination, Vietnam, Ford’s favorite son status....there are so many variables, you’ll see what you want to see.
Thanks, Reeses, I think you’re right. I happily moved far away from Detroit in 1969.
(And away from CA six years ago.)