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Rolling along Iowa’s gentle hills in mid-August is usually like surfing a green tidal wave. Corn fields are so lush that plants often tower several feet over the heads of crop scouts setting out to analyze yields. This year, some scouts were crawling around on their hands and knees to find ears of grain during the annual expedition.

Crops have been smashed down to lay flat across the ground after a powerful derecho swept through earlier this month, bringing high winds and hail. The soaring height of the plants makes them particularly vulnerable to strong gusts, which bend, fracture and then can ultimately snap the green stalks. Knocked over corn often suffers yield damage, and it can be a nightmare to harvest with machinery unable to move normally through the fields.

“Down corn wears your equipment out much, much faster. It wears you out mentally, physically, economically, financially,” said Chad Rockow, 44, who produces corn, soybeans and hogs in Iowa’s Scott County. “It’s one of the worst challenges a grain farmer can face.”

“We went from having probably one of our greatest crops in many, many, many years to potentially one of the most frustrating, stress-testing, marathon, ugly harvests—just a disaster.”

Crop scouts were assessing the damage this week as part of a four-day annual tour of the Midwest grain belt. They found that yields in Iowa are likely to be lower than historical averages, with Iowa Secretary of Agriculture Mike Naig estimating this week that the storm impacted as many as 14 million acres of the state’s farmland.

This is just the latest blow to Midwestern farmers, pummeled first by the U.S.-China trade war and then by the pandemic. Coronavirus lockdowns served a serious hit to corn demand by delivering a knockout to the ethanol biofuel market. All that comes on top of years of stubbornly low prices and huge overhangs of inventory, which haven’t eased much under the administration of Donald Trump and his often-touted “love” for farmers. At least 20,000 homes and businesses in central Iowa are still without power after the Aug. 10 storm, according to utility Alliant Energy Inc.

There are nascent signs that farmers’ patience with the president is starting to wear thin. While support for Trump is still strong in rural America, there’s dissatisfaction at the margins. A survey of at least 500 farmers showed 71% plan to vote for Trump, down from 89% in April, agriculture publisher DTN Progressive Farmer said this week.

Iowa is a key state for American agriculture and politics. It’s the No. 1 grower of corn, the country’s biggest crop, and a major soybean and hog producer. It’s also among Republican-leaning states critical for Trump to win in November. The state, with six electoral votes, backed Trump over Hillary Clinton four years ago, but went for Barack Obama in 2012 and 2008. Iowa also will help determine whether Republicans keep control of the Senate, with a heated race between incumbent GOP Senator Joni Ernst and Democratic challenger Theresa Greenfield, a farmer and businesswoman.

Trump, so far, has continued to curry favor with farmers not just on social issues but also with aid. His administration delivered $19 billion to help mitigate the impact of Covid-19 on agriculture, which came on top of $28 billion in two trade bailouts to make up for farmers’ losses in the tariff dispute with China. Iowa growers could see more aid to help with the storm fallout.

“If you ask most American farmers, they don’t want any help. They just want the market price to support their business,” said corn grower Rockow, who describes himself as a “more of a conservative,” but didn’t want to discuss who he’s voting for.

For farmers like Rockow, the insult to add to the injury of the storm may be that for all their suffering, they may not see much market impact.

Even if last week’s derecho wiped out half of Iowa’s corn crop (a highly unlikely scenario), that would mean a loss of about 1.37 billion bushels. That would be devastating for the state’s farmers, but may not move the needle when it comes to prices because of expectations for a bumper national harvest—currently forecast by the government at a record 15.28 billion.

More realistically, Arlan Suderman, chief commodities economist at StoneX, estimates the damage in Iowa is likely closer to 200 million to 400 million bushels. A loss of that size might be barely a blip in the national context, especially considering that this week’s crop tour has found bigger-than-average yields in growing areas including Ohio, Illinois and Nebraska.

Corn prices are down about 12% this year as stay-at-home measures kept cars off the road, reducing demand for ethanol.

“We don’t expect it to have a broad impact on the overall price of grain or impact on the market for grain. We think it’s going to be very centralized,” said Kevin McNew, chief economist at Farmer’s Business Network, an ag tech platform.

The biggest impact may end up being a ripple effect from grain storage lost to the storm, which blew down silos and destroyed crop bins. Iowa Secretary of Agriculture Naig said that damage to commercial storage means that about 60 million bushels worth of space has been wiped out, and considering that farmers in the state hold a roughly equal amount of storage as commercial centers, the total for the state could be closer to 120 million bushels.

Iowa’s on-farm grain storage in 2019 totaled 2.1 billion bushels, the most in the U.S., while off-farm, or commercial, was 1.51 billion, also the largest in the country.

The storage loss means that come harvest time, which will start as early as next month, some farmers could end up scrambling for a place to keep their grain. That could force them to sell more than they’d like into a market with tepid demand, pressuring prices and adding to their woes.

On Mike Schmidt’s farm in DeWitt, Iowa, the roof blew clear off of one of his grain bins and another suffered severe damage, which he’s he hoping to be able to repair, but is also worried it may also end up needing to be torn down.

“It’s not a thing you can just easily get fixed,” said Schmidt, who’s growing corn and soybeans on 5,000 acres. It takes time to get replacement parts, and there aren’t enough builders and electricians to quickly recover from all the damage that’s hit the area, he said.

“We won’t have a grain facility for this fall. We are going to have to haul it to other elevators, but they also sustained damage,” said 40-year-old Schmidt, who thinks some people will decide not to rebuild and instead just retire.

“If I were retirement age, I probably would think the same way too.”