The U.S. national average price of diesel topped $6 a gallon in September for the first time ever, as fuel supply disruptions pushed up transportation costs in the country.[8140608] President Trump has allowed the sale of cheaper, dyed diesel on highways to reduce the historic fuel-cost spike ahead of the midterms.[8140608] The president is promising $90 Medicare rebate checks ahead of the midterms, but critics say the hidden cost could be the increased use of dyed diesel.[8065872][8140608]