The average price of a gallon of diesel fuel in the United States reached another record high on Saturday, with data published by the American Automobile Association (AAA) showing the national average now stands at $5.88.

Diesel is the workhorse fuel of the US economy, powering the trucks that carry the large majority of the nation's freight as well as farm machinery, construction equipment, and trains, so swings in its price tend to ripple through shipping costs and consumer goods well beyond the pump.

A Saturday report from Axios found that incumbent Republicans are increasingly worried about how skyrocketing gasoline and diesel prices will affect the 2026 midterm elections, especially because their own internal polling shows voters are blaming the price hikes on President Donald Trump's war with Iran.

"Diesel's at an all-time high," one GOP operative told Axios. "Gas is about $4 a gallon. We can't message that away."

Another Republican source told the outlet that GOP candidates have no realistic option of distancing themselves from the president and his unpopular war, given the firm hold he has over the voters they will need to turn out in crucial races.

"We have no choice," the source said. "We're stuck on the boat with him whether we like it or not."

Fuel prices have historically been a persistent political vulnerability for incumbent parties, as voters encounter them daily and often weigh them heavily when judging economic management ahead of national elections.

US Secretary of Transportation Sean Duffy attempted to frame the record-high diesel prices as outside the president's control during a Saturday interview on Fox News.

"When you look at diesel, you have to look at Russia and Ukraine," Duffy said. "Russia was a major exporter, the second-biggest exporter in the world, on diesel. They stopped their exports, so that puts pressure on the global market. But President Trump has pushed American energy dominance, we are producing more energy now than in the past."

Duffy added that "it's only President Trump who's trying to drive these prices down," even as critics point to the president's war as a primary driver of the increases. The exchange was highlighted by journalist Aaron Rupar:

https://x.com/atrapar/status/2096245087881556462?ref_src=twsrc%5Etfw

A report published Friday by The Associated Press noted that diesel costs have a particularly strong effect on food prices, since the fuel powers both farm equipment and the trucks that deliver food to grocery stores.

"Fuel accounts for roughly 15% to 30% of the total cost of food, according to the Independent Grocers Alliance, a grouping of 7,500 global supermarkets," the AP reported. "So higher diesel costs often result in more expensive groceries, although it can take a while for energy shocks to wind their way through the supply chain."

Rising grocery costs have weighed on US consumers for years, and during the 2024 presidential campaign Trump vowed that grocery prices would come down starting on his very first day in office. As the midterms approach, how sustained high diesel and grocery prices interact with that pledge is likely to remain a central point of contention between the parties.