Tell City was a deliberate colonization effort by Swiss-Germans, and was intended to be named Helvetia. It is now named for William Tell. It has a relatively large French ancestry population around 9%, but is otherwise typical for the area German and American, with around 10% Irish and English. Dubois to the northwest (and inland) is much more German, while Crawford to the east is more American.
Swiss-German suggests Protestants (Calvinists) - true?
If yes, that might be part of the answer. While others and I myself have noted various cases of Catholic German Americans swinging heavily towards Romney, Protestant German Americans appear to have mostly remained loyal to the Democrats. This is at least indicated by results in heavily Protestant German American counties in Wisconsin (e.g. Dane) and Minnesota. Perry County might be another point in case.
Abortion might be one of the key issues that divide Catholic and Protestant German Americans.
If this is true, it really doesn't apply to Pennsylvania Dutch areas (Swiss Mennonites, though relatively few are actually Amish) like mine. Look at Lancaster County, PA or Holmes County, OH.
Yeah, I don't think his analysis is right at all. Rural Protestant Germans were almost never Democrats historically (all three aspects being factors tending to cause one to be a Republican in the past).