Jean Paul Sartre wrote an essay on anti-Semitism which briefly showed some promise of touching on truth. But then he totally screwed it up by asserting baldly that only the bourgeous classes were anti-Semitic, not workers, a crock if ever there was one.
Sartre was a Stalinist apologist. He defended the Gulags.
Camus broke with Sartre broke over it with Camus condemning Stalin and siding with freedom.