It’s a type of social contract. In the traditionalist culture, being non-secular, they ascribed it to “God”, but, as you know, there is no God, so it was actually up to real people belonging to religious institutions, the clergy. Since the Enlightenment, people have tried to replace God with Nature; this has often been a bad joke with terrible consequences, but eventually secular paradigms took over and tried to reason the contracts into shape, to make them more consistent. There’s a lot of philosophy about this and I can’t summarize it as easily. But what you’re seeing today with Trump and the traditionalists, this anti-secularism, is a desire to return to the pre-Enlightenment state with its contracts and monarchy and aristocracy determined by “God”:
https://en.wikipedia.org/wiki/Great_chain_of_being
The racism was used to sell to white “middle classes” the dream of becoming rich and lording it over the “not white” who were separated, segregated. In this context, white is a class, not a race, and it is most definitely not something that can just be dispelled by informing people that it’s all made up by capitalists to divide the people. You can think of this class as “honorary petite bourgeois” for those workers.
Even if it’s true what you say, you don’t get to demand that people who’ve experienced racist attacks and discrimination suddenly forget about it and reclassify that experience as just a misunderstanding.
Some reading for you:
Toward a Political Philosophy of Race by Falguni A. Sheth | Goodreads
A People’s History of the United States: 1492 - Present - Zinn Education Project
“Exterminate All the Brutes”: One Man’s Odyssey into the Heart of Darkness and the Origins of European Genocide by Sven Lindqvist | Goodreads - this one is also an HBO documentary
SETTLERS