Immigration is the natural way of things in the US. The white Europeans overpopulated the natives and in turn ( and in time ) it seems they themselves will be surpassed by non-Europeans.
I believe this is what angers many Americans and is the major argument on white supremacy sites.
Fascism is on the rise in Europe and I think it will spread. Desperate people do desperate things. What I found funny is that some member of a European Right Wing group was talking on TV the other day and he said most of their groups do not even consider the US to be a white country anymore and will be "cut off" in their "New World Order".