The fact that liberals and progressives tend to be more altruistic than conservatives and supremacists doesn't mean that they're incapable of intolerance and tribalism. If X and Y are opposing groups and I (for whatever reason) side with Y, then it's easy to stereotype and ostracize everyone with whom I associate X. But (as a self-styled progressive), I claim that my defense of Y shows that I'm so open-minded I can't be guilty of bigotry toward X.

Happens all the time. We saw sexism and misogyny from some of the most progressive (in their eyes at least) partisans during the past two presidential primaries.

Reductive / simplistic binarism ("All Jews favor Jews over everyone else"; "I'm allying with Palestinians so I have no responsibility to seek allyship with Jews") is just as available to progressives as to regressives.