Those two things aren't actually at odds, even though they're both incorrect. Just because something is a social construct instead of biological doesn't mean it can't be used as a basis for something else.

What would actually be contradictory would be to say that "these people are black, Asian, or Hispanic, but this vast group of people don't have a race" that cannot possibly square in their worldview. They won't, can't, get rid of the "white" race as a concept. They just say that white isn't a protected class.

You've gone too deep.