You're commenting and acting as if said that he shouldn't pick a black woman at all
By making explicit promises, you're creating the issue of future segments of people wanting those same promises as well if another Supreme Court seat comes open in his presidency. You're already seeing it now with the question being asked of Jen Psaki whether Biden will make future promises when it comes to nominating an Asian or gay person to the Supreme Court.
To be 100% honest, I could care less who he picks to the Supreme Court. That's what you fail to realize by trying to make my comment come off as