Actually, if you close off the importation of a critical commodity with a high protective tariff, and you're a big enough customer, you can bring down the world price. Plus you quit exporting hard earned capital to the people who hate you.
Technically our largest source of imported hydrocarbons is Canada ~ a polygon if there ever was one ~ but we can continue to import their oil while taxing that sent here from other markets ~ e.g. Venezuela.
That's a box ~
I don't see any room for Obama and his running dog lackeys in there.
Porcupine.
Hydraulic.