Lol, I think you give those lefty liberals too much credit. I doubt most of those equality hippies understand the genetics of humans.    I don't think they were ever arguing against the fact that there are MHC I incompatibilities between ethnic groups.    We are all the same under the skin is more a metaphorical point they argue that the capability of a human being has no relation to their genetics.    You would look pretty stupid telling a liberal Ah HAH! See! Humans have these things called immune systems that will reject organs without compatible MHC's    The difference's described here don't really add anything to our understanding of race theory.