My Dad is from Iowa so I feel okay saying this: Iowa farmers are, uh, very simple people who are mocked by townies in Iowa. They, not the "white working class", are the ones moving from Obama to Trump. Notice how well Obama did in southern Iowa. This is a region filled with smallholders who are kept afloat by subsidies and who have been hit hard by a downturn in commodity prices. This is where the swing will come from.
It's widely known that farmers in Iowa are a class that's pretty dumb. Have you heard an Iowan speak? They sound like their brain has been soaked in corn syrup.
oh ffs, enough of this