Interesting that Franklin county is a rural county almost 100% white.
My instant take is that most or all of these counties are rural and white. They don’t want to spend scarce money to purge the voter rolls. These counties would tend to have honest elections. One county had 5000 population.
I grew up in Franklin county. if you wanted a govt(city, county, etc) job...you had to be a democrat....at least that was the way it was when i was there a few decades ago. Still have relatives that live there.
it has been in decline since the coal mines closed many years ago.