I agree with you that race is a structural concept of capitalism, economics, and socio-spatial segregation. I say that race has always been a social construction with the sole purpose of legitimizing hierarchical discrimination. The color line has always been the power line and the poverty line. As the power structure of colonialism shifted from conquering new territories to consolidating territorial control, the myth of race was created. Academics have for decades been increasingly dealing with the social construction of race and its concrete consequences. Awareness of the problems caused by race-based hierarchies has increased alongside awareness of the similar problems caused by gender-based hierarchies. Much recent attention to the issue of race is, I think, due to the Trumpian obsession with reasserting the pre-Civil Rights hierarchies.