A few years ago, a liberal wrote a book "What's Wrong with Kansas", which decried that state's conservatism. Perhaps a conservative should write a counterpoint on Iowa.
From what I've read, it's not that Iowa is white or rural or of German ethnicity.
It's that Iowa is Democrat, and by association, that elects a lot of leftists into office.
It became so ensconced in the Democratic Party during the Great Depression, when this state was hit particularly hard. The lies of "greedy rich" were pounded into their heads, and into their children's heads, so that it is a multi-generational thing.