Our standard conceptions of race are also meaningless political rhetoric, so calling race a social construct seems entirely appropriate then.

We still, at least subconsciously, apply the "one drop rule" in all sorts of situations, including describing the race of the current US president. Sub-saharan Africa contains more genetic diversity than everyone else, yet we lump them all together in one "race."

Yes, there are distinct genetic differences between various groups of people, and many of those differences have real-world consequences. But the relation of those groups with what we call "race" is almost zero.