As others have already said, the demographics in this region were ripe for a red swing, and Trump was their guy. Interestingly enough, this was usually fairly Republican territory for awhile, but had a big swing to the left after the farm crisis and being attracted to people like Clinton and Obama.
Iowa was in fact the only state to swing Republican in '92, after voting anomalously Democratic in '88 in response to the farm crisis, with the decline in small farming and consolidation of agribusiness accelerated by that sowing the seeds of its current partisanship. Many other states that had voted far more relatively Dem than usual in '88 (MT, SD) also had anemic D swings and strong Perot votes in '92; MT flipped from Bush to a very narrow Clinton plurality while flipping from left of the nation to right of it!
True, although the point I was making was that the gains made during the farm crisis in the Greater Driftless Area were mostly retained from 1992 to 2012, especially compared to the area's partisanship before 1988 and after 2012.
