Manzi carefully explains the limits of the idea:
A $2 per gallon a gas tax sustained for decades would surely reduce U.S. petroleum consumption somewhat, but logically by a small fraction of the difference between the U.S. and Germany. It might even be a good idea as compared to other ways to raise revenue, which is one thing it would certainly do effectively – mostly because burning a gallon of gas is so valuable to people that they’ll keep doing just about the same amount of it, even if you double the price. Of course, that’s also exactly why it’s not a very effective way to address projected global warming problems, or de-fund hostile regimes.
The Dish 