A huge amount of domestic oil would still be in the ground if the US had European level taxes on fuel. That would be political suicide though as so many Americans have built a lifestyle on the basis of having unlimited supplies of relatively cheap fuel.
In theory, it wouldn't need to be political suicide, because oil products were also lightly taxed in Europe, till they weren't. Somebody somewhere along the line managed to make the decision to raise taxes, knowing it would be highly unpopular.
In practice, politics in the USA is already a suicidal activity in itself, regardless of the policies you wish to implement, and I fail to see why anybody wants to go into politics these days. I seriously wonder why there are American politicians that still give a damn about public opinion, considering that public opinion these days just goes with whatever is the latest culture war, but I guess I just don't understand politics.