People here arguing that the US should accept more immigrants from all over the world because "the US has been built on immigrants" need to get their facts straight:
The "National Origins Formula" was only abolished in 1965. Before 1965, US immigrants were 90+% white.
I'm not arguing a certain side here, but want to point out that those who say "the US has been built on immigrants" might be nostalgic to a past that never existed.