dunno about the rest of the cities, but I tried to find some data on wealthy republicans in baltimore. only about 8% of all the people in baltimore are registered republicans. pew forum doesn't even break down republicans by income, presumably because there are so few. [0]

it's true that wealthy people dominate politics in pretty much every municipality in the US, but at least in baltimore the shot callers are likely all dems.

[0] https://www.pewforum.org/religious-landscape-study/metro-are...