Iowa swung fiercely to Trump. Will it swing back in 2020?

DES MOINES, Iowa (AP) — Few states have changed politically with the head-snapping speed of Iowa. Heading into 2020, the question is whether it’s going to change again.

In 2008, its voters propelled Barack Obama to the White House, as an overwhelmingly white state validated the candidacy of the first black president. A year later, Iowa’s Supreme Court sanctioned same-sex marriage, adding a voice of Midwestern sensibility to a national shift in public sentiment. In 2012, Iowa backed Obama again.

All that change proved too much, too fast, and it...