This will surely backfire in the long term
Many exceptionally talented tech workers & engineers in developing countries such as India and even in developed countries such as the UK will emigrate to the US to enjoy the (real or perceived) higher standard of living and higher salary. If they can no longer do that, those people are instead more likely to stay and work for a company in their own country, which will in many cases be competing with American companies. An Indian company will always be able to undercut an American company on price, and if they can also compete equally on technology it is bound to affect American sales.
The "brain drain" has long given America a huge competitive advantage and allowed them to become World leaders in many fields. Stopping that policy will be their great loss, and the rest of the World's gain. Ten mediocre American engineers will never be able to do the job of one brilliant foreign engineer (though it will keep domestic unemployment figures down in the short term).
Biting the hand that feeds IT
