nik0tine -- There is a difference in immigration and illegal immigration. Many Americans would support legal immigration, but not people crossing the border illegally. I would agree that people who disagree with any kind of immigration might could be considered anti-Mexican (or, since you've changed it, anti-Hispanic), but there's no argument against those who don't have a problem with legal immigration. It's like saying some people are anti-poor because they'd rather poor people go out and work for their money than steal it.
Only so much legal immigration would be allowed though. The government will only allow a certain amount of hispanics to immigrate into this country legally. Why? Because racism would undoubtedly be spawned from it, and thats a fact. When there is a large number of one race, the majority gets racist. Before the second world war, countries like Britain, France, etc. would only allow so many Jews to immigrate to thier countries. They were fleeing Nazi persecution, but after X amount of Jews had immigrated, they closed thier doors and said "Sorry, you're just going to have to deal with the concentration camps." After a period of time, America won't allow any hispanics to immigrate even legally.