Farmers helped propel Trump to the White House. Their loyalty is being tested by his trade war.

In good years, cargo trains moving west along the flat, sweeping grasslands of North Dakota’s plains are a sign of money rolling in. Today, as tariffs from America’s largest foreign soybean market -- China -- threaten to upend the industry, many trains sit idle.“There are no shuttle trains leaving. There is no nothing,” said Joe Ericson, the 38-year-old president of the North Dakota Soybean Growers Association. “They can’t get rid of the beans.”In conversations with more than 50 farmers, producers and agriculture experts in five states representing each of the five food groups, one trend was clear: The once-deep ties to President Donald Trump have frayed over the past year. But they remain intact for a small majority of farmers CNN spoke with ahead of the critical 2018 midterm elections. Democrats, who see an opening with Trump’s trade war, will likely struggle to make inroads with these voters.The President gives all of them plenty to complain about. They grumble about his tweeting -- that’s not their style -- and what his trade war has done to their bottom lines. But if the President’s re-election were held tomorrow, most of them would back him. They trust Trump, and many believe Democrats don’t understand or largely ignore their way of life.