To pick a black female simply because Biden wants a black female is the very definition of affirmative action.
They're playing chess.
They actually don't give a crap whether the nominee is a black female -- it could be a Martian. They want a socialist activist judge, and they know that if that person is sufficiently intersectional (e.g. black and female), they can call anyone opposing the nomination "racist" and/or "sexist".
In a few years "transgender" will enter the mix. We are so screwed.