President Trump has ordered the Department of Justice to investigate Exxon Mobil and Chevron for allegedly keeping gasoline prices artificially high while crude oil costs have plummeted. The announcement, made June 24 via Truth Social, marks an unusual moment: a Republican president going after Big Oil.

Here’s the thing. Crude oil prices have dropped roughly 36% from their May highs. But the average US gasoline price sits at $3.93 per gallon, only about 14% lower than the May peak. That gap between crude savings and pump prices is what has the administration reaching for the investigation lever.

The math that set off the alarm

For context, the national average for a gallon of gas was $2.76 back in January. That means even after crude’s dramatic slide from May peaks, consumers are still paying roughly $1.17 more per gallon than they were six months ago.

The American Petroleum Institute has pushed back on the simple math, noting that gasoline and crude oil prices don’t move in lockstep. Supply chain disruptions, refining capacity constraints, and distribution logistics all create friction between what happens in commodity markets and what shows up on the gas station sign. In English: there are legitimate reasons the two prices don’t track perfectly, but whether those reasons account for a 22-percentage-point gap is exactly what the DOJ will presumably try to figure out.