Biologically speaking race doesn’t exist. The problem is we not only pretend it does but pretend that it matters a great deal. Skin color is one physical feature among many and it makes no more sense to argue that it matters or qualifies one for membership in a “race” than it does to argue height or hair color does.
It’s true, accepting that there is just one human race (I prefer the term species) won’t wipe out centuries of discrimination based on the false belief that skin color makes us members of this or that “race” but it would go a long way toward eliminating centuries more of it. Ultimately, racism is the belief that race is real. No one can arrive at the conclusion one “race” is superior to another without first wrongly embracing that belief. While we may never become so color blind as to literally not see the color of each other’s skin any more than we fail to notice the color of each other’s eyes, shouldn’t we be trying to get to the point where we don’t see skin color as salient? Isn’t that what MLK meant when he articulated his dream that we would someday judge each other by the content of our character instead of the color of our skin?