Moslems and other America hating liberals...otherwise, people would vote with their pocketbooks.
It would certainly encourage domestic development. You could start with a modest rate and start ramping it up as domestic development increased.
Given a future business friendly power structure in DC, and since there is much untapped resource on federal lands, and since (theoretically) the American People own those mineral rights; why couldn't/shouldn't there be strings attached to the disposition of that oil?
Why should a lessee be able to sell that crude into the global market without an export penalty, when it could be dumped here to increase domestic supply and lower the cost?
Especially if that lessee happens to be a foreign interest.
We have such international agreements and organizations like GATT and the WTO that limit what we can do unilaterally. I doubt either party will want to withdraw from them.