Iowa was supposed to be fertile ground for Donald Trump’s primary challengers. Its population is disproportionately evangelical, and voters were expected to coalesce around a more faith-driven alternative. But that’s not what’s happened. This past summer, Trump was polling at around 42 percent in the state, a lead that has only continued to grow. Increasingly, it looks like Iowa is on track to coronate the former president. So when we visited the state fair in August, it was less to follow around a bunch of the candidates while they were milking a cow or flipping a pork chop, but rather to ask Iowa’s voters: What’s different this time?