i understand that he's trying to stir the pot, but this is a case of your enemy's enemy being your friend - because the people trying to make an issue out of this are also stirring the pot, in a way that is incredibly damaging to the left.
i should point out the obvious, if rarely stated, truth: identity politics is not in any way left-wing, and attaching it to the left is completely wrong, if done with so much glee by the right. identity politics is a subset of neo-liberalism, and for that reason you will see these arguments come from the centre, and not the left. i have argued repeatedly that foucault was actually a conservative, that his system was fundamentally burkean and that his followers belong on the right. it is only a function of the strange political spectrum in the united states that these ideas could be associated with the left, but, as mentioned, they are truly not - they are a part of the neo-liberal consensus, upheld by the trudeaus and clintons of the world and denounced by socialists and anarchists of all sorts.
this is actually an article by a liberal, who is criticizing a conservative ideology, which is in turn attacking sanders, who in this case is being a liberal. sanders' statements are pretty boilerplate, in the intersection of the left with liberalism, but inherently liberal in concept - we are all equal before the law, perhaps because we are equal before god and perhaps just because we like it better that way. as mentioned, you won't find many people on the left that will break with liberalism when it comes to ideas of race. the left mostly disagrees with liberalism on questions of economics.
i actually think that the democrats really need a moment of self-reflection around this, because the position they are adopting is not one of liberalism but one of hierarchy and racial privilege, merely flipped over and placed on it's head. is it the case that so many people in america think they're entitled to wealth or privileged due to their upbringing? the media would tell you it is; i don't think the data quite supports that. but, the party seems to want people to believe it, whether it currently is or isn't true.
the sanders campaign is probably going to want to retreat from these kinds of arguments. i actually think that this is not just wrong but dangerous - that liberals and leftists have to get together on this and win the debate.
sanders is completely right, and anybody suggesting otherwise should be roundly denounced and ripped apart over it.
https://www.politico.com/magazine/story/2019/02/20/bernie-sanders-left-2020-225190