It’s Chippewa Valley Farm-City Day, and hundreds of schoolchildren are swarming the grounds of Denmark Dairy, which stretches for nearly a mile along County Road B in Dunn County, in western Wisconsin. They are laughing and chattering to one another and petting young calves. The dairy, one of the largest in the region, sustains a herd of twenty-four hundred cows on more than four thousand acres, each milked by machine three times a day. Some of that milk finds its way up the road to the Swiss Miss plant, in Menomonie, which makes more than fifty million boxes of hot-cocoa powder every year, among other sugary delights. Each kid receives a small container of Swiss Miss vanilla pudding while making the rounds.

Dennis Kragness, who is seventy, has been farming here since 1973, expanding in hard times that have bankrupted other families. In the past fifteen years, nearly half of the state’s dairy farms have shut their doors. Farm bankruptcies in Wisconsin last year were higher than in any other state, triggered by years of low commodity prices. As Karen Gefvert, the Wisconsin Farm Bureau’s government-relations director, put it, farmers “get up every morning and they lose money.” Adding to the stress, President Trump’s trade battles and the stalled replacement for NAFTA are limiting access to foreign markets while his demonization of undocumented immigrants stymies efforts to secure a badly needed labor force. At Denmark Dairy, which Kragness runs with his son, Karl, half of the forty-person staff arrived from Latin America, presenting papers that the farm keeps on file. Kragness wishes that he could recruit workers in their home countries and see them obtain documents allowing them to travel back and forth. “Let them cross the border legally. If they could set up a green-card system,” he told me. “We need these people. They’re good people. I don’t know how we would run the farm without them.”

Yet you won’t hear Kragness criticizing Trump. “I don’t have any issues with the President, with what he’s done or what he’s said. If others would work with him, he could solve it,” he said, seated at a folding table beneath a white party tent set up for Farm-City Day. He’s glad that Trump is challenging China on trade, which “had to be corrected.” He praises his attacks on the Federal Reserve chairman, Jerome Powell, which aim to drive interest rates lower and strengthen economic growth ahead of the 2020 election. Nor will you see him considering any of the Democratic Presidential candidates. “I’m not in favor of any kind of socialism,” he said. “We’re a capitalist farm.”

Kragness is just one voter. But, as Republicans and Democrats look for clues about the rural vote leading up to the election, his views reflect the loyalty of Trump’s staunchest supporters and reveal the challenge facing Democrats aiming to seize the narrative from a skilled political showman. In interviews this month with more than two dozen people in Dunn County and in neighboring towns, I found that both parties are gearing up earlier than ever, vowing to contest counties that voted for Barack Obama, in 2008 and 2012, before lurching to Trump, in 2016, helping him win the state by twenty-two thousand votes out of three million cast. “Is it backfiring?” Mark Hagedorn, a dairy expert at the University of Wisconsin-Extension, asked about farmers’ decision to back Trump. “I think we can argue that six ways to Sunday.”

Wisconsin has a history of close Presidential elections, with Obama’s thrashing of John McCain, in 2008, and Mitt Romney, in 2012, the exceptions. Al Gore won the state by a scant six thousand votes, in 2000, and John Kerry won by eleven thousand, four years later. Even Trump’s surprising victory offers warning signs for Republicans. He received fewer votes than Romney, but benefitted from a desultory Democratic campaign effort and voters’ antipathy toward Hillary Clinton. To overcome Democrats’ advantages in Milwaukee and Madison, and their strength in an increasing number of suburbs, Republicans need to run up the score in rural counties like Dunn. That’s what happened in 2016, when the state’s forty-six rural counties supported Trump over Clinton by nineteen points, according to a tabulation by Craig Gilbert, the Washington bureau chief of the Milwaukee Journal-Sentinel. He found that more than five hundred localities, with a median population of less than eight hundred, chose Trump after voting for Obama four years earlier. Brian Reisinger, a Republican strategist, told me, “The past several elections show clear as a bell that there is no room for error.”

The late-summer landscape of Dunn County could not look more bountiful, with acres of tall corn and leafy soybean plants that stretch across rolling hills toward the horizon. The potato and kidney-bean harvest is well under way, soybeans are next, and farmers are already beginning to consider what next year’s market will bear. One morning, when the sunlight was golden and the day not yet hot, I drove along winding two-lane roads to see Jim Holte, who farms about four hundred and fifty acres near the town of Elk Mound. Holte started, in the mid-seventies, with dairy cows, then switched to a beef herd. This season, he planted two types of soybeans, for seed and for non-G.M.O. food, aiming to squeeze a price premium in a year made tough by trade uncertainty and the worst spring weather he had seen in forty years. Technology and experience are making farmers better than ever at growing things, he said, “But the margins are smaller. If I had to make a living on what I can grow on four hundred and fifty acres, it’s not possible.”

Holte draws a paycheck as the president of the Wisconsin Farm Bureau, a role he has had for nearly seven years. He has seen how American farmers keep producing more than the U.S. market will bear, forcing prices lower, a phenomenon that long predates Trump. That’s one reason that foreign markets are so important. “We’re too good at what we do,” he said.

A dozen miles away sits the Holm Boys Dairy, where Doran and Mariann Holm, a husband-and-wife team, no longer produce milk for sale, an all-too-common circumstance with milk prices just starting to emerge from a devastating five-year trough. The Holms raise organic dairy cows for others, and both work outside the farm. Mariann inspects organic farms and Doran works at Organic Valley, a vast dairy coöperative that collects more than a billion dollars in annual revenue. After we toured the barn, where Mariann showed me the idle milking equipment, we sat at the kitchen table to talk politics. “Why did everybody vote for Trump? They wanted somebody who talks plain, who cuts through the B.S,” she told me. “I don’t think they blame him for what’s going on, though he may be exacerbating things. They’re praying to God that anything he does will work out.”

Holm has never voted for the Democratic Presidential candidate in a general election, but she voted in the 2016 primary for Senator Bernie Sanders. “I don’t know if I’m so far on the right I’m on the left. Or so far on the left I’m on the right,” she said. A few months ago, she travelled five hours to Storm Lake, Iowa, not to see Republicans but Democrats. Four Presidential candidates were talking about the rural economy, and she wanted to hear how Senator Elizabeth Warren and others would fix a system that seems stacked against small farmers and businesses. “We need Teddy Roosevelt!” she exclaimed. “We need people to break up the trusts. We need people to get the money out. That should be a Republican issue. I don’t think this comes across as fringe or loony-bin. Now I think people recognize it. In our criminal-justice system, who gets off and who goes to prison?” To her, voting for President too often seems to be a matter of choosing the lesser evil. “Give me an option,” she said. “If it’s not going to be Trump, who’s it going to be?”