Yes, but it likely wouldn't make a difference because he doesn't demonstrate the willingness to inspect his own biases and be honest with himself. This is a condition in which many, if not most modern liberals are stuck.
There are fundamental premises that need to be considered. One of them is cultural relativism. Once one acknowledges that not all cultures are equal, and that some are destructive, it is much easier to discuss what is acceptable and what is not. The politically correct view, and the view generally taught in universities, is that all cultures are essentially ‘equal’, except American culture - which is assessed as traditionally insular, racist/bigoted, colonial, oppressive of the rest of the world, and less intellectual.
To hold and propagate this view is to ignore facts, and is in many ways a type of cult belief. Nonetheless, this is the view that you hear from the left recurrently. I remember Hillary being asked whether she ‘loved’ America. She answered, ‘I love the America that can be’. That is the viewpoint of many on the left, and it is too often expanded to included rejection or derision of all traditional American cultural norms. These include rejection or derision of Christianity, marriage, defined gender, achievement based on effort (”you didn't build that”), etc. etc.
History has shown us that not all cultures are equal, and implores us to take the best and leave the worst as we move forward. Cannibalism, head-hunting, human sacrifice, fights to the death in the Roman colosseum, cock-fighting, slavery, torture, are all ‘cultural’ attributes that we've rejected as barbaric and wrong. Even liberals would agree on this (mostly - although some might argue that we have no right to judge cannibals and head-hunters). Once we accept that not all human cultures and activities are equal, then we can legitimately discuss what types of human behavior are destructive and should not be tolerated going forward.
Or, we can be like de Blasio.
liberalism/progressivism/socialism/communism/Islam are all cult experiences. They require absolute, unquestioning loyalty to survive. They are each absolutely dependent upon the ignorance of their adherents and their willingness to be sacrificed morally and intellectually for the good of their cause.