It’s been two years since Donald Trump fell in love with the word groceries. He seemed to believe the word alone would convey his compassion for the common man. “The beautiful but simple word ‘groceries,’” he rhapsodized. “I won on that word.”
Now we have a word Trump is losing on: diesel.
The fuel used in heavy-duty trucks is named for the German engineer Rudolf Diesel. In 1894, Diesel invented a spark plug–free engine that requires a form of crude oil that’s thicker than gasoline. These engines are used in farm machinery, tactical vehicles, container ships, and, above all, heavy-duty trucks.
Diesel prices have surged since Trump took office, and especially since February 28, when he started the war in Iran. When Joe Biden left at the start of 2025, diesel cost an average $3.63 per gallon. Just this month, that price blew past an average of $5.85 to a record high of more than $6.50. Disruptions to oil shipments, notably in the Strait of Hormuz, are pushing up crude oil prices, while reduced diesel supplies have left fuel markets tight all over the world.
On Monday, Tom Kloza, the chief oil analyst at Gulf Oil, was not reassuring. “Monday morning price average for US diesel is $6.51/gal,” he posted to X. “Looks like plenty of panic liquidation in futures and spot markets, so these highs may prevail for a while.” Evidently, even Trump woke up long enough to express a hazy interest in diesel, talking up a possible ban on U.S. diesel exports. “Let’s not send out the diesel,” he said Tuesday. “That could have a little bit of an effect on regular automobile gasoline because when you do that, you know, it’s a sort of a flow.” This Hail Mary bafflegab has exactly zero chance of creating policy change before the midterms, much less reducing diesel prices.
Inflation on groceries and gas hits everyone. But skyrocketing diesel prices aim a missile squarely at the voters Trump can least afford to alienate. Only a highly specific demographic at the pump, after all, knows its way around the diesel nozzles. Fully 90 percent of diesel truck buyers are men. More than 84 percent identify as white. Most strikingly of all, truckers have a ram-tough party ID. According to one analysis, Republicans purchase eight heavy-duty trucks for every one purchased by a Democrat.
And while Trump and his party have entirely failed to calm public fears about gas prices—“I love the inflation!” Trump said in June—they’ve done far, far worse with diesel, where prices are spiking even more steeply.
About one in five Trump voters now regrets their 2024 vote, according to one opinion-research organization. No wonder social media is filled with the diesel demographic, onetime Trump voters, raging at the president. “Hey, Donald Trump, man, it just cost me $179 to fill up my diesel!” shouts a shirtless trucker at the top of his lungs. “Six-dollar diesel is killing truck drivers!” shouts another. (Reports spread of an imminent strike by truck drivers, but this seems so far to be rumor only.)
“This is Trump’s fault,” said populist firebrand Marjorie Taylor Greene in a video on X last week. She blamed Trump’s war in Iran and the ensuing global fuel crunch. “It’s $8.49 for diesel in California,” she said. “It’s $6.59 in Georgia. I don’t care if it’s Georgia or California. It’s way too high.”
With a new poll showing Trump’s approval rating at an anemic 29 percent, Greene incurs few political costs for lashing out at him. But Greene is also an intuitive grandmaster of the diesel class. She has an especially keen eye for their issues: data centers, the Iran war, the Epstein files, and now diesel fuel. These are the issues Trump is dying on.
On diesel, Trump has repeatedly claimed that all fuel inflation is a “small price to pay” for thwarting Iran’s nuclear program. When he talks about diesel at all, he deflects to his favorite whipping boy: Ukrainian President Volodymyr Zelenskiy. “Mr. Zelenskiy has to do one thing,” Trump said from the Trump International Golf Links in Ireland this month. “He has to stop knocking out diesel fuel in Russia.”
Does he, though? If so, good luck getting Americans to believe it. Blaming the American president for price inflation is a way of life here. Live by it; die by it. Trump did nothing but savage Joe Biden for high prices born of the Covid pandemic. Now he expects a pass for inflation he’s actively helped create.
The top three heavy-duty trucks in the U.S. are American: the Ford F-Series Super Duty, the Ram Heavy Duty, and the Chevrolet Silverado 2500HD. These model names lean hard on the word “duty.” Veterans disproportionately buy them. After all, military vehicles also use diesel, including Humvees, five-ton cargo trucks, and tanks. Trump’s dalliance with a shiny red all-electric Tesla last year did not impress this crowd.
Others in Trump’s administration have tried to frame big-rig trucking as patriotic in itself. In July, Transportation Secretary Sean Duffy announced the “Freedom Hauler” campaign, which is designed to get veterans to haul freight for a living.
“There’s never been a better time for America’s former service members to get behind the wheel of a big rig. Trucking requires the precision, independence, and discipline that they forged in the military—there’s no one better to tackle the challenge.”
In Iowa, Democratic Senate candidate Josh Turek is well aware of the diesel class, and the fast-approaching Iowa harvest season, which runs on diesel. In his campaign, he has called for a pause on diesel exports, a suspension of federal gas taxes, and an opening of strategic oil reserves. Recently, none other than the Hawkeye State’s Republican Senate lion Chuck Grassley, 93, who is not up for reelection, seconded Turek’s efforts in what amounted to an ad for the Democrat. Turek’s opponent, Republican Representative Ashley Hinson, was forced to join in but looked like a straggler.
By alienating the diesel class, Trump may have bitten the final hand that feeds him. Diesel is certainly the word to watch in these final weeks before the polls. If nothing else, it’s excellent shorthand for the rambunctious MAGA coalition that political scientists have been trying to understand for a decade.
