Bleeding Heartland has an excellent article on the state of Democratic Politics in Iowa. It includes a sophisticated analysis of the issues in light of the ANES survey.
Iowa had one of the largest ’12 to ’16 swings in the country. Obama always considered the state a bellwether and the personal connection he felt to the state was the reason his final 2012 campaign event was there.
I not sure I agree with everything, or even most of what is written. But it is interesting.