The radical left has never been a reliable ally in the fight for human rights
Uh, then who are the "reliable all[ies]" of the human rights movement? I don't see how the people with the deepest-seated commitment to egalitarian principles are anything but the primary allies of the humans rights cause.
Anti-semites don't really have a deep-seated commitment to egalitarian principles.
Us liberals who actually support universal human rights are the good guys. The radical left is a good ally at times but discussions like this is a useful reminder that it can't be relied upon. Currently, the radical left cannot be relied upon to protect Jews, for example.
This. And the far-left outside the Western world didn't really have a good track record on civil rights...