Quoting now from a new book by Tara Zahra — The Great Departure: Mass migration from Eastern Europe and the making of the free world, Chapter 6:

“In 1952, Truman attempted to launch a U.S. escapee program, hoping to offer 300,000 new visas to refugees. Once again lawmakers successfully blocked immigration from Eastern Europe. The Immigration & Nationality Act of 1952 reaffirmed the quota system’s discrimination against East Europeans, [who were] depicted as a threat to Western civilization: ‘I believe that this nation is the last hope of Western civilization and if this oasis of the world shall be overrun, perverted, contaminated or destroyed, then the last flickering light of humanity will be extinguished. I take no issue with those who would praise the contributions which have been made to our society by people of many races, of varied creeds and colors. America is indeed a joining together of many streams which go to form a mighty river which we call the American way. However, we have in the United States today hard-core, indigestible blocs which have not become integrated into the American way of life, but which, on the contrary are its deadly enemies.’” (Source: Congressional Record, March 2, 1953, p.1518)

Like I explained in my original post: This is not new — We just forget. Because — by design — previous waves of foreigners become woven into the very fabric of our society.