Prior to the Nazi's the ideology was called something else.

Eugenics. Manifest Destiny. White Australia Policy. etc.

German extremists bundled these together under their heinous flag and used it against their 'enemy', the Jewish people living in Europe at the time - but you are right that the eugenics and white supremacy movements came from, principally, American sources, and have been the motivation and justification for countless similar atrocities ever since the fall of the Nazis.

The key thing is that the brand changed, but the effect remains the same: degradation and deterioration, if not outright extermination, of cultures deemed inferior to white, western ideals.

We continue this outrageous ideology in the form of the "War on Terror", which is just Nazi ideology, rebranded for the pallets of a gullible, decadent, over-fed American public ... who would tear down the walls of the White House if it were to ever outright parade the swastika, but who are nevertheless patriotically inclined, as good robots are, to get behind whatever threat their mighty fighting men have determined is the Next Big Bad Guy™ ...