when reading it for the first time a lot of people imagine a direct correlation between blood supremacy and racial supremacy because of the way that rowling draws parallels between them, the malfoys are racist, voldemort is hitler, etc etc.
but honestly, i think a wizarding world with diverse pure-blood lines of many races and ancestries is a more interesting reading of it.
the wizarding world is already historically very separate and distinct from the muggle world and i think it’s interesting to imagine a wizarding world that has historically used magical pedigree, completely separate from race, as the primary object of discrimination and ideological superiority
it’s a reading that allows the Gaunts to be mixed-race descendants of both the black wizarding Peverell lineage and the white wizarding Slytherin lineage while still being obsessively concerned about blood purity and it maintains a route for Marvolo Gaunt to see Merope’s partnership with Tom Riddle Sr., a member of an extremely wealthy muggle family whose physical descriptions and historical social position heavily imply whiteness, as traitorous.
i think it’s a much more compelling reading to view the historical wizarding world as lacking much of the concepts of racial supremacy that Muggle ideologies have produced, having been much more intimately concerned with magical blood supremacy than physical ancestry and complexion. it’s worth remembering that white supremacy is a historical construct that rose directly out of western imperialism and colonialism and not in any way an innate tendency of humans. it’s entirely possible (and to me, a very interesting thought) that the historical wizarding world’s extensive isolation from muggle actions and affairs might have kept it largely ignorant of the muggle world’s racial ideologies.