U.S. on-highway diesel reached $6.285 a gallon on Sept. 14, according to the Energy Information Administration, as supply disruptions tied to the U.S.-Iran conflict and Ukrainian attacks on Russian refineries drove prices higher. Economist Steve Hanke said the increase was hurting farmers and truckers during harvest and argued it was turning both groups against President Donald Trump. Farm fuel costs were up $11 an acre for corn and $7 an acre for soybeans from the previous year. Reuters reported the same increases, citing Purdue University economist Michael Langemeier. Higher diesel prices have also prompted calls for possible restrictions on diesel exports. Farmers and truckers face limited ability to pass on higher costs: farmers generally cannot set commodity prices, while independent truckers often pay fuel bills upfront. Economists warned diesel could remain elevated for at least another year, raise the cost of agricultural inputs and contribute to bankruptcies. Available national data, however, do not establish a broad political shift among farmers or truckers. The Associated Press reported fuel-cost frustration among voters, including some Trump supporters, while Sen. Chuck Grassley (R-Iowa) called the prices harmful to farm income and urged Trump to consider an export embargo.