As far as illegal/legal immigrants, I always get frustrated when people don't like immigrants by and large because of the illegal population and the problems associated. (not saying PADPM or anyone else was saying this, it just sparked the thought in my head).
I worked construction with many /legal/ immigrants in San Antonio, and they were some of the hardest working people I've ever had the pleasure of working with. Additionally, you won't find many people that absolutely /hate/ illegal immigrants like a legal Mexican immigrant does.
Nothing pisses them off more, after jumping through so many ridiculous hoops to get here legally to work here and pay taxes, than a fellow who crossed the border without papers and works some of the same jobs without paying taxes. They also don't appreciate that it took some of them years to get approved to come here, and see other people that just came across without having to wait.
They also appreciate the opportunities in this country more than most natural born citizens I've met, because they've lived in a place that didn't have them.
Not quite the same scenario as Canadians, etc., who didn't exactly come from a third world country, but still the point is the same...legal immigrants are what made this country the place it is, and we're better for it. My beef will never be with you fine folks :-)