How about studying the years that Jews were slaves in Egypt and elsewhere then six million murdered in Nazi Germany!
As an example of how liberalism overpowers logic, I was having dinner with Jewish friends when they went into a tirade about how Americans institutionalized slavery, presenting it as an exclusively American sin. I asked them about Jews being slaves in Egypt, suggesting that slavery has existed about as long as humans have. They left in a huff and ended our relationship. Sad.