Gasoline prices in the U.S. are flirting with a milestone not seen since 2021: a national average below $3 per gallon. The combination of tepid summer demand, surging imports, and a bearish oil market has put downward pressure on prices—even during what’s typically peak driving season. In the runup to the July 4th holiday, the national average fell to $3.14 per gallon, according to GasBuddy. This is the lowest summer level in four years, according to AAA. Finished motor gasoline product supplied (a proxy for demand) during the July…