The Neo-Nazis, who have reared their ugly heads, with the advent of Trump, would be well advised to learn some history lest they have to repeat it.
Prior to World War II and the rise of Hitler, Germany despite its economic problems, was the world's preeminent scientific nation. It's language was offered by almost every High School in the U.S. almost as a requirement to take college courses in science. It was necessary to do research in much original scientific literature. Pre Hitler German science benefited from the input of what Hitler called "unter menschen"(sub-humans) such as Slavs, and Jews - for example atomic physics was considered, by Nazis, as a "Jewish science, the Nazis assured they would never be the first to get the atomic bomb", by forcing the flight of German and Hungarian Jews from Europe.
When Hitler invaded the Soviet Union and conquered most of European part of the Soviet Union, it was the "unter menschen" of Soviet Asia, for the most part, who manned the Siberian factories that outproduced Nazi dominated Europe, not only in quantity but in quality of goods, but also supplied the fresh troops that overwhelmed and destroyed an entire German army at Stalingrad.
The Nazi principle of "racial purity" brought the German people, among other things, destruction of much of their Homeland; the loss of 1/3 of their original territory; German became a backwater language in Science and was replaced by English.
When "racial purity" comes to America, there is no reason to expect a better outcome.