Unfortunately, by reducing supplies, a windfall profits tax will only lead to even higher prices. Still, if Congress really wants to "do something" about high gasoline prices and global warming, it can always try rationing.

To lower gasoline prices permanently, you can reduce demand, increase supply, or do both. Congress long ago capped supplies by proclaiming from on high: Drillest thou not offshore, nor in ANWR. The next obvious step for our solons is to cap demand by rationing gasoline, and then gradually reduce the quantity of ration coupons.

"Trading" in coupons would be encouraged to ensure gasoline is allocated to uses of only the highest value. So Congress could reserve quantities of ration coupons for key lobbyists and their clients. Environmentalists could buy up coupons and "retire" them, lowering gasoline sales even more. Refineries could continue to produce gasoline, but as consumer demand would be sharply limited (and declining), oil companies would be forced to reduce the prices they charge. No more windfall profits! And lower carbon emissions!

For legislators and environmentalists – if not average citizens – this plan has other virtues: As ration coupons are reduced, consumers would increasingly clamor for more electric cars, cars that ran on French-fry oil, and "flex-fuel" cars that burn everything from gasoline to garbage. Eventually, gasoline could just be banned, reducing prices to zero and eliminating all ill-gotten profits.