Almost everyone, of course, is against illegal immigration. It's corrosive to have laws you can't enforce. Furthermore, wanting to slow down legal immigration doesn't make one a racist. Wilson knows this. Immigrants, whatever their legal status, are generally optimistic, hardworking, adaptive people willing to do the jobs that residents won't touch.
Economic studies show that they give far more to the economy than they take away.
The few people discouraged from immigrating would be far outnumbered by those who would come anyway, but once here might feel they had no stake in a society where their families were permanently disenfranchised. Wilson is attacking the American dream. Consider General Shalikashvili, the new chairman of the Joint Chiefs, who immigrated here with his parents at age sixteen. The general's father served as a major in the German SS Waffen and lied about this when immigrating. A clear, documented violation.