That "race" is as real as "culture" is, or "sex", or "gender".
So an attempt to abolish identity politics simply by declaring "Those differences don't exist!" won't succeed. They do exist, and sadly, they're considered by some people when making decisions that affect other people's lives and well-being (while, arguably, those shouldn't be considered).
The immutability of race is one of the reasons why we ought not discriminate on the basis of race, but the parent is addressing the question of whether or not race is “real” and our inconsistent treatment of race and culture, another social construct.
This might be of high interest to scholars, but for the regular Joe on the street the realities are way more important. And my feeling is that the OP is trying to shift the discussion from reality (which can be addressed in a way or another) to philosophical debate (well, good luck with that)
So an attempt to abolish identity politics simply by declaring "Those differences don't exist!" won't succeed. They do exist, and sadly, they're considered by some people when making decisions that affect other people's lives and well-being (while, arguably, those shouldn't be considered).