This is what happens with a lot of liberal Jewish people. They want to find the one perfect liberal black person who will be their Messiah. They always forget that black people are people, just people. They're so obsessed with their mistaken belief that liberal black people are not just people and humans just like everyone else, that they're convinced that all black liberals are sacred and somehow superhuman. Then when a liberal black guy or woman inevitably behaves like a human would, they get shocked and petulant and deeply disturbed. Like a deeply devout child who has just been told there is no god.
For a lot of liberal Jewish people, even if they're atheists, the idea that a liberal black person is not a sacred angel of god just doesn't compute. The reality that lefty black people are just humans like every other group : good, bad, disappointing, weird, unpleasant, sometimes nice etc. is terrifying to most liberal Jewish people.