Why shouldn't I hire foreigners?
I run a startup on the west coast - I have Brits, Russians, Saffas, Germans, Dutch, Israeli, 4 kinds of foreign chinese, Japanese, Indian, Africa, Iranian, Jordanian, 3 former bits of Yugoslavia, Chilean, both the "natural born citizens" are 1st gen Chinese. I just hired our first European-American.
They all have work permits, visas or citizenship, why should I care which? They all pay tax here, consume stuff here and contribute to the local economy - and most importantly build our business.
They are all also scientists and engineers and are all paid irrespective of skin color or nationality.
Why should I prefer people born here?
If it's purely racial then should I only hire white Americans, only Christians, only Protestants, only the same branch of the church as you or the same eye color ?