Obviously, there are physical differences in peoples that are related to their ancestry, and to the extent that one talks about race as a mere matter of these physical differences, race exists. But does race carry with it any significant intrinsic differences in moral worth, intelligence, or industriousness? There's no scientific evidence that says so. Any differences here are trivial.
___The idea that race "doesn't exist" is a sloppy way of saying that race is a category of no significance, other than as a focus of prejudice.
___Unfortunately, the American left has this annoying and misleading practice of using metaphors for rhetorical emphasis, and then forgetting that the metaphor is not literal language. Metaphors are stretched language, and are false to the extent of the stretch, so to the extent that those on the left can't tell their metaphors from literalisms, they succumb to creeping delusionality. This has become quite alarming over the past 15-20 years, and it's no wonder that there are so many mental illness professionals in far-left voting districts. (The far-right has its own problems, but they're not relevant here.)
___If you go to one of the major left wing websites (MoveOn, DailyKos, Truthout), you'll find a tone of shrillness and of an inauthentic indignation that enjoys the indignation more than it hates the object of it. It's too self-congratulatory to be genuine. All those boomers who got hooked on the gratifications of their self-proclaimed moral high-ground in the sixties have introduced a couple of new generations to the opiate of the self-righteous but loony left, whose only notion of corruption is the sort that's found by following the money. They're blind to their own corruption.
___These are not stupid people, but they are just a wee bit insane. (I once knew a guy with a 200 IQ who used every point of it to defend his denial of his serious mental health issues. The far left is like him.) And that's why we end up with so many proclamations like, "Race doesn't exist".