Why is it important to you that we have a "prejudice" for Mexicans in our immigration system?
That is a good question. It is logistics. Nothing more. We have a BOATLOAD of entry level employees on our doorstep and a country that is achingly poor. Just makes sense to give them preference, to me.
It isn't some romantic notion of Mexicans being "more noble" or something. As a matter of fact, Mexicans are sort of despised by most of Latin America as being more crude and lowbrow and ignorant, especially by those from South America. You would NEVER hear a businessman in Colombia say "CHINGELO" in frustration. They sort of sneer at Mexicans like Europeans view the Irish.