The point you are missing is that it is intentional. It was planned by government, politicians, corporations (donors). Hart Cellar was the American Kalergi Plan, albeit a lighter version. All of those politicians said hey this won't upset the ethnic makeup of the country not biggie. It's also happening in W. Europe to countries that were never immigrant countries of the Americas.
The Proud Boys are multi Ethnic/Racial. Trump voters are against illegal immigration. And I also think that legal immigration needs to be ramped back some. That kinds what the USA did in 24' and there was a large emphasis in government to get all of the people in the USA assimilated to being American.
So the question is why do you support mass illegal immigration and legal immigration with the intent of making people of European ancestry a minority?