The law of Supply & Demand still applies. Excess refined fuels are exported which props up the high Futures Market for domestic gasoline, diesel fuel and jet fuel.
http://money.cnn.com/2011/12/05/news/economy/gasoline_export/index.htm
How in the world is excess supply going to "prop up" price?
Gasoline prices are high for the same reason gold jewelry is high. The base material it is made from is high in price.
Domestic demand is down, but globally, petroleum demand is up. Since we import far more crude oil than we produce ourselves, we are quite tied to the global prices.