[WS;] yeah. Graeber (Debt) argues that slavery had initially little support in Europe for historical reasons, and if it was justified at all, this was by reference to Roman legal concepts - i.e. since it was "legal" to have humans as property in Africa, it was "legal" to sell and buy that property. Social Darwinism emerged after the legal notion of slavery was eliminated, and the inferior status of people of color or non-Western ethnicity more generally, had to be justified on different grounds.
I would be careful in making racism accusations, though. Once this reasoning became established in popular culture - no doubt by effort of racist promoters - it became a cultural trope, "stock knowledge" , a canned narrative that "made sense" of what people saw. People do accept such narratives all the time without harboring any ill intentions.
-- Wojtek
"An anarchist is a neoliberal without money."