I mean...the largest increase, and the longest year-to-year increase of gas prices in the past 30 years happened 2002-2008, which was hardly Democrat controlled. Prior to that they were basically flat since 1990. The past two presidents saw an increase the first half of their years in office (4 years for Obama, 2 years for Trump), and a drop the last half.

Not really sure a political conclusion is warranted here.