Why are the Cincinnati suburbs so red?

[Sol]

The historical profile of the Cincinnati suburbs is pretty similar to WOW actually--an older industrial city with a lot of Germans, and a lot of German catholics, plus particularly nasty and polarized white flight. Cincinnati is also a step more conservative than Milwaukee however because of closer cultural ties to the South and to "Butternut Ohio," which gives it an even more conservative bent compared to metro Milwaukee, where most internal migration historically was of Yankees.

Cincinnati is also a fairly parochial place without a ton of in-migration or growth (but without the bottom falling out either) and that means it's somewhat "dealigned" from usual electoral patterns.