Shane knew another farmer, Joe Bragger, who was attending the vice president’s rally the next day, so we arranged to have dinner afterward with Joe and his family at their home.

Once that was taken care of, we could return to planting corn. Shane’s John Deere 8335R tractor is equipped with state-of-the-art GPS and can pretty much direct itself, automatically aligning the rows of seeds being planted. Yes, I wanted to drive it. (Though when I learned a new one sold for $330,000, I understood why he wasn’t eager for me to take the wheel.)

Shane told me about his family’s history as farmers in the area, which stretched back to the 1850s when his ancestors first arrived as immigrants from Norway.

We talked about weather cycles; the effect of a cold snap on early corn (it’s like the brain freeze headache that strikes when you eat ice pops too fast); commodity prices and loans; his wife’s teaching job, his three daughters and white deer hunting ; why he voted for Mr. Trump; the impact of tariffs; federal farm aid; and China’s leaders.

Then we drove off to the next field.

“Growing up, the last thing I wanted was to be a farmer,” he said. Now he loves it. “I don’t know what else I’d do.”

But it is a tough life. Over the previous week, Shane had spent 125 hours in the tractor and had missed his daughter’s performance in a concert the night before. “No one should have to work this hard to make a living.”

Shane said he and other farmers he knows wanted a businessman in the White House. Most important, he said, is that Mr. Trump “loves farmers.”