I am not all white people.
New white people are not me.
Foreigners coming to the US doesn't replace me. I'm still here. Once I'm dead, I do not give a shit who's in the US.
The predominantly-white culture of the US is nothing at all like the predominantly-white culture of the US of a few decades ago because cultures change. The US is and always has been a cultural melting pot.
Your argument is based entirely in racism. Fuck off back to /pol/ with that bullshit.
(Also, you're misinterpreting that UN report)