Around 1900 most of the immigrants came from Europe. Increasingly, this was Eastern and Southern Europe. Resistance started increasing, at one extreme by the KKK, but in a general sense throughout the population. Policies changed, the depression hit, and it dropped. 1965 came and the closet Marxists were in charge. Ted Kennedy sponsored new legislation:
"Out of deference to the critics, I want to comment on … what the bill will not do. First, our cities will not be flooded with a million immigrants annually. Under the proposed bill, the present level of immigration remains substantially the same … Secondly, the ethnic mix of this country will not be upset … Contrary to the charges in some quarters, S.500 will not inundate America with immigrants from any one country or area, or the most populated and economically deprived nations of Africa and Asia. In the final analysis, the ethnic pattern of immigration under the proposed measure is not expected to change as sharply as the critics seem to think. Thirdly, the bill will not permit the entry of subversive persons, criminals, illiterates, or those with contagious disease or serious mental illness. As I noted a moment ago, no immigrant visa will be issued to a person who is likely to become a public charge … the charges I have mentioned are highly emotional, irrational, and with little foundation in fact. They are out of line with the obligations of responsible citizenship. They breed hate of our heritage."(Senate Part 1, Book 1, pp. 1-3)
If a Senator mentioned the importance of ethnic mix today, he'd be strung up by his balls. But even Teddy did it in 1965--things have changed utterly. At any rate, every single word was a total falsehood. The above quote has the greatest concentration of mendacity that I've ever read.
Look at the numbers in the link above. The United States is being turned into a different country, a Latin American country, an Asian country, an African country all at once, many, many times faster than it turned European after 1492.
Obviously, some people have reason to be happy about this, but drop the bullshit. Policy is not guided by "populist racial attitudes". If it was, the immigration level would be NEGATIVE six million/decade. Numbers don't lie.