Here’s what happened.
Record diesel prices are creating a growing economic challenge for President Donald Trump as farmers, truckers and small-business owners face sharply higher fuel bills heading into the final weeks before the midterm elections.
The pressure is especially noticeable in Iowa, where agriculture and transportation remain central to the state’s economy.
In the Des Moines metro area, the average price of diesel reached approximately $6.34 per gallon on September 22, according to AAA. One year earlier, the price was about $3.49.
That means an 80-gallon fill-up that cost roughly $279 a year ago now costs more than $507 — an increase of approximately $228 every time the tank is filled.
For a family filling one vehicle, that would be painful enough.
For a farmer, trucking company, delivery business or contractor operating several diesel-powered vehicles or machines, the additional costs can quickly reach thousands of dollars.
And Iowa is far from alone.
Diesel Prices Reach Record Levels
The national average price for diesel reached approximately $6.53 per gallon on September 22, according to AAA.
That was up from about $3.69 one year earlier and represented the highest national diesel average recorded by AAA.
The increases matter because diesel plays an essential role throughout the American economy.
Long-haul trucks use it to move food and consumer goods across the country. Farmers rely on diesel-powered tractors, combines and other equipment. Construction firms use it in heavy machinery, while delivery services and local businesses depend on diesel-powered commercial vehicles.
When fuel expenses rise substantially, businesses eventually have to decide whether to absorb those costs or pass some of them along through higher prices.
That is why the diesel problem extends far beyond the numbers displayed at filling stations.
Midwest Refinery Shutdown Adds Pressure
The Midwest has faced an additional complication following trouble at ExxonMobil’s large Joliet, Illinois, refinery.
The refinery was taken offline after a power outage, and Exxon subsequently reported that floodwater overwhelmed a pump at the facility.
The Joliet refinery has the capacity to process roughly 275,000 barrels per day and is an important source of gasoline and diesel for Midwestern states. Reuters reported that the facility can produce approximately 11 million gallons of gasoline and diesel per day.
The disruption arrived at an especially difficult moment.
Global diesel supplies were already tight because of disruptions involving energy production and refining capacity in several parts of the world.
Reuters reported that U.S. diesel inventories have fallen unusually low for the time of year and that tight global supplies could continue well into 2027.
For Iowa farmers and businesses, that creates another layer of uncertainty.
Iowa Farmers Face a Cost Squeeze
Few industries depend on diesel as heavily as agriculture.
Farmers need fuel for tractors, combines, irrigation equipment and trucks used to transport crops, livestock and supplies.
As a result, a jump of nearly $3 per gallon can dramatically change the economics of running a farm.
Fuel also represents only one of several major expenses.
Farmers have faced higher costs for fertilizer, equipment, transportation and other agricultural inputs, while international trade disputes and geopolitical instability have created additional uncertainty.
That combination has increased political attention on energy prices in farm states.
Iowa is particularly important because agriculture remains a major part of the state’s economic identity, even in and around its largest metropolitan areas.
The communities surrounding Des Moines include farms, agricultural businesses, colleges, manufacturers and rural service centers that depend heavily on the farm economy.
When farmers spend more on diesel, the effects can spread throughout those communities.
Why Iowa Matters Politically
The economic issue also arrives during an unusually competitive political year in Iowa.
Although Republicans have held an advantage in recent statewide elections, Iowa also has a substantial number of voters who are not formally affiliated with either major political party.
Official Iowa Secretary of State figures from May 2026 showed approximately 692,000 active Republican voters, 496,000 active Democratic voters and nearly 589,000 active voters registered with no party.
That large unaffiliated bloc means economic conditions can receive considerable attention during competitive campaigns.
Iowa’s 3rd Congressional District, centered around the Des Moines area and extending into rural parts of the state, has also changed party control multiple times during the past decade.
Fuel prices therefore are not simply an economic story in Iowa.
They are becoming part of the political debate.
Ashley Hinson Calls for Diesel Relief
Republican Senate candidate Rep. Ashley Hinson has responded by calling for several measures intended to reduce fuel costs.
Her proposals include temporarily suspending the federal gasoline tax, pausing diesel exports, expanding the availability of E15 ethanol fuel, restoring a biodiesel tax credit and creating a diesel relief program aimed at farmers and truckers.
Hinson said Iowans should not have to absorb higher costs connected to the conflict involving Iran and called for the war to reach a “successful and immediate end.”
Her comments are notable because she is not the only Republican pressing the administration over diesel prices.
Other GOP lawmakers from agricultural states have also pushed for steps to increase domestic diesel supplies.
Iowa Sen. Chuck Grassley has been among the Republicans urging action on diesel exports as farmers and transportation companies cope with record fuel costs.
The Trump administration has so far resisted proposals for an export ban, amid concerns that restricting exports could create additional problems in global energy markets.
Republicans Confront a Difficult Economic Issue
The debate puts Republican candidates in a complicated position.
They can support the Trump administration on many policies while simultaneously asking Washington to address an economic problem affecting constituents back home.
Hinson has also taken a more critical position regarding the duration of the conflict with Iran.
Reuters reported that both Hinson and Michigan Republican Senate candidate Mike Rogers have recently called for the war to end more quickly as fuel costs have become an increasingly prominent campaign issue.
Those statements do not necessarily represent a broader Republican break with Trump.
But they demonstrate how rapidly rising diesel prices are beginning to influence campaign messaging in states where farming, manufacturing and trucking play major economic roles.
High Diesel Prices Can Reach the Grocery Store
Consumers who never purchase diesel directly can still feel the effects.
Nearly everything Americans buy spends at least part of its journey being transported by truck.
Food must move from farms and processing facilities to warehouses and supermarkets. Building materials have to reach construction sites. Manufactured products travel between factories, distribution centers and retailers.
When transportation companies pay substantially more for fuel, some of those expenses can eventually appear in the prices consumers pay.
Reuters reported that diesel prices have risen considerably faster than gasoline during the current energy shock and that the added fuel expense has become a meaningful cost for the broader economy.
That makes diesel prices relevant even to Americans who drive gasoline-powered cars.
Farmers and Truckers Want Relief
The immediate concern in Iowa is straightforward.
At approximately $6.34 per gallon, filling an 80-gallon diesel tank in Des Moines costs more than $500.
For a commercial operation that fills several tanks every week, the difference from last year’s prices can be enormous.
Farmers are facing similar calculations during a season when fuel consumption can be particularly heavy.
That explains why lawmakers are discussing ideas that would normally receive less attention, including export restrictions, fuel-tax holidays and targeted assistance.
Each approach carries tradeoffs.
An export restriction could potentially increase domestic supply, but energy-industry groups and some analysts argue that interfering with established fuel markets could produce unintended consequences.
A federal fuel-tax holiday could provide immediate savings at the pump, but it would also reduce revenue used for highways and infrastructure unless Congress replaced those funds elsewhere.
Those debates are likely to continue as policymakers search for ways to respond.
Trump Faces Pressure Over Energy Costs
The political question now facing the White House is how quickly diesel prices can come down — and what, if anything, Washington should do about them.
Global conditions make that difficult.
Reuters reported that diesel markets remain unusually tight worldwide because of disruptions connected to conflicts involving Iran and Ukraine, reduced refinery output in several regions and historically low inventories.
Domestic refinery disruptions such as the shutdown in Joliet add another challenge.
President Trump and Republican lawmakers therefore face an issue that cannot necessarily be solved through a single policy change.
For voters, however, the economics are much easier to see.
A farmer who fills a tractor sees the price.
A trucker filling a commercial rig sees the price.
A small-business owner operating several delivery vehicles sees the price.
And eventually, consumers may see part of that additional expense reflected in the cost of products transported across the country.
With diesel now at record levels nationwide, fuel costs have moved from an energy-industry concern into a broader economic and political issue.
For Trump and Republicans campaigning across America’s farm states, Iowa offers a clear example of why the price of diesel could remain an important issue through Election Day.