Don't tell me you didn't see this coming: The high price of gas forced consumers to buy less, resulting in less tax revenue -- which governments want to replace.
Of course, what government always wants is more tax revenue, but for years people have been predicting that, if the liberals every got the decrease in gas consumption they said they wanted, it would bite them.
The same goes for if people quit smoking. Or eat healthy (healthy food is less processed, so it passes through fewers hands...). Or use public transportation (these things always run in the red; more riders won't help if they require more buses/trains).
Generally, there is a cost to every gain, and a good side to every bad. Conservatives (I didn't say Republicans) understand this and try to stay out of the way; liberals end up stepping on their own feet.