It’s still difficult to see Trump losing Iowa in November

By Stuart Rothenberg Iowa gave Barack Obama a resounding 9.5-point victory over John McCain in 2008. Four years later, Obama’s margin shrunk to 5.8 points against Mitt Romney. But in 2016, something odd happened. Donald Trump carried Iowa by 9.4 points — a dramatic change in the state’s recent voting behavior and close to the same winning margin as Obama’s eight years earlier. Iowa had gone Republican before, of course. It voted narrowly for George W. Bush in 2004, and it backed Ronald Reagan twice, in 1980 and 1984. But Michael Dukakis carried it comfortably in 1988, and Al Gore’s narrow victory in 2000 seemed to suggest Iowa was shifting ever so slightly toward the Democrats. That is what...