What was Mandel's appeal in rural western Ohio? For that matter, I've heard that some of the counties he was strong in further east are Amish or Amish-adjacent; was he seen as especially strong on school choice?
These are heavily-evangelical areas, with high levels of church attendance, and line up closely with the areas where Ted Cruz was strong in the 2016 primary, in spite of the statewide primary being largely polarized between Trump and Kasich. At the grassroots level, Mandel attracted an enormous amount of support from the hard-socon set, although that's not the main message that came across to outsiders and Mandel tried hard to reach out to other voters.
Those Western Mandel counties aren't so much Evangical as rural Catholics. Overwhelmingly German. The Catholic population is especially strong in the western half of those counties, but is quite present in the eastern half as well.
They are about as socially conservative voters as you'll find anywhere in the state.
