This writer has an interesting insight, IMO:
It has to do with the liberal emphasis on “indiscriminateness.”
They were raised to believe that indiscriminateness is a moral imperative. That the only way to be moral is to not discriminate between right and wrong, good and evil, better and worse, truth and lies because your act of discrimination – discriminating between these things might just be a reflection of your personal discrimination, your bigotries.
They were raised to believe that indiscriminateness is a moral imperative because its opposite is the evil of having discriminated. The second bullet point, and this is an essential corollary, is that indiscriminateness of thought does not lead to indiscriminateness of policy. It leads the modern liberal to invariably side with evil over good, wrong over right and the behaviors that lead to failure over those that lead to success. Why? Very simply if nothing is to be recognized as better or worse than anything else then success is de facto unjust.
There is no explanation for success if nothing is better than anything else and the greater the success the greater the injustice. Conversely and for the same reason, failure is de facto proof of victimization and the greater the failure, the greater the proof of the victim is, or the greater the victimization.
Once you understand this facet of liberal thinking, many of the illogical things that liberals believe make more sense.
https://townhall.com/columnists/johnhawkins/2016/06/18/why-liberals-support-muslims-who-hate-everything-they-stand-for-n2180270