Claims of racism arise from the assertion that colonialism forced people to adopt a binary of male and female. Because us brown people had no idea about men and women before we were taught by our wise and civilised white educators.
I think it’s based on two spirit people, Hijras etc but doesn’t really address the fact that sex is still binary regardless of cultural roles, even for those before colonisation.
As for white supremacy, I don’t really understand but here is Emily gorcenski explaining
mobile.twitter.com/EmilyGorcenski/status/1088180524504571908
If anyone can parse it and translate, I’d be intrigued to finally learn the connection between believing that humans are dimorphic in sex and believing that white people are superior to all other races and should benefit from other people’s oppression.