Back in the hey day of "scientific" racism there were a lot of claims that were made about Anglo-Saxon people vis a vis other groups. Most of it is pretty easily rejected, even by the 30. Just better tools of linguistic analysis, genetics, and basic standards in stuff like anatomy got people to reject stuff like phrenology, which had served as the basis for a lot it.

But, the racism associated with the term got worked into a lot of stuff, like immigration law and the medical profession. It mostly now is associated with stuff like keeping Jewish people from receiving refuge from the Nazis or slavery or sterilizing people of color or lower classes or colonialism.