I think one thing that separates the WOW counties from other suburban areas in the US is that they aren't becoming more diverse or more educated. I think long term, they are becoming slightly more D, but not to the same extent as other suburbs, and we may see a dead cat bounce in 2024 depending upon who the GOP runs.
I am not sure if it's so much about diversity or education in the case of Milwaukee. The WOWs are among the most well-educated counties in the entire state of WI and most other Midwestern and northern suburbs aren't particularly diverse either.
My guess would be that it has something to do with the size and population of the Milwaukee metro in general.
