Sadly, mainstream public opinion in this country is given shape by tabloid newspapers and their flavor of the month.
A lot of this stuff is hyped up to sell papers.

What we do have in the US is a lack of a clear self image which opens up people to worrying that they are losing it with immigrants when they were never quite sure about what it was in the first place.

Firstly, with regards integration. If you're worried about the "Mexicans" not integrating, what are your neighbors names and how often do you speak to them? What local activities do you take part in? The US is drifting away from close knit communities and it's -nothing- to do with immigrants.

Welfare recipients, there's a million more scumbag US born and bred claiming various benefits illegally (and think they have a RIGHT to do this) than there are immigrants. Yes there are a number of bad apples that have immigrated here but there's many more already here.