You basically hit the nail on the head. It will also discourage competition. Why would a competitor enter this market knowing before hand the extreme amount of taxation that he/she will incur? This will also lead to gas shortages, so basically we will have the 1970’s all over again. Price caps, gas shortages, gas lines, and new investing or competition will be discouraged into entering the market. All of this will of course raise the price of gas in the long run. Also the government will have more money to throw around and that equates to wasting more money and flushing it down the toilet. Not the mention the immoral nature of invading the market and basically stealing money from regular businesmen and your average investor.
Another thing to consider is the sheer amount of retirement investments in the energy industry. These are currently popular picks in 401 k’s, and for good reason too. As previously mentioned, a windfall tax would not necessarily have an instantaneous effect, but would ultimately drive down the overall market capitalization of these stocks thereby hurting many middle class Americans who are heavily invested.
Taxes also raise the cost of doing business so there is a chance that it might be passed on to the consumer. For instance gas prices did rise pretty quickly when the United States Congress eliminated the oil companies loopholes. I am not certain if the loophole reductions did this but I bet there is some connection. A windfall profit tax, which is pretty much a tax that targets the oil companies will do everything people have mentioned above and raise the overhead cost of the business.
I can’t even be sure about things like that- he can just use the excuse of “Well it would’ve been much worse if we didn’t go through with all my plans”.