After doing some research, the only counties without some kind of obvious connection to coal that swung 20 were:
Calhoun, IL
Rush,IN
Stark,ND
McMullen, TX
Waupaca, WI
All 8 in Utah except Carbon. Obviously Utah had a rally around the Morm effect.
So, excluding coal and Mormonism, 5 counties swung 20% or more.
Calhoun, IL: 53,5% German ancestry (2000 census), went for Obama in 2008
Rush, IN: 32,5% American ancestry, 27,6% German, 13,4% Obama swing in 2008
Stark, ND: 57,9% German ancestry, 13,1% Obama swing in 2008
Waupaca,WI: 53,1% German ancestry, 17,7% Obama swing in 2008
McMullen, TX: 20% German ancestry (2010) - only 500 votes in total
There seems to be a pattern here, which also extends to several +20% R-swing 'coal counties', e,g. Dubois, IN (64,7% German), Knox, IN (28,6% American, 26,3% German), Clay, IN (30,7% American, 25,7% German), Elk, PA (42,8% German), Clinton, IL (62,1% German), Clark, IL (26,4% German, 24,4% American), Jasper, IL (49,2% German), Jersey, IL (39,2% German), Wabash, IL (32,4% German, 22,8% American).
I also noted that some of the more heavy (> 10%) R swings in Texas occurred in "German Texan' counties (Lavaca, Fayette, Burnet, Clay, Karnes, Kimble, McCulloch, Mason, Parker)
Having been raised in Waupaca County Wi, the true surprise is how far it swung D in 2008. 2008 is the first time the county went Democratic since 1936. 2012's results are more normal.
So what made a sizeable number of rural counties in the mid-west with strong German ancestry swing to Obama in 2008, and swing back even more heavily to the Republicans in 2012? Obama's 2008 pacifist appeal and Berlin speech? Or were Romney/ Ryan (Boehner) just a better 'cultural fit' for German Americans than McCain?