what confuses scout about what her teacher says about not persecuting anybody

Her teacher says racist things about blacks.

One day during Current Events, Scout's class gets into a discussion about Hitler and the persecution of the Jews. Her teacher, Miss Gates, speaks at length about how the German dictatorship allows for the Jews to be persecuted by a prejudiced leader, but she claims that in America, "we don't believe in persecuting anybody." Scout finds Miss Gates hypocritical because she remembers that on the day of Tom's trial, she overheard Miss Gates say that she thought it was, "time somebody taught them a lesson, they thought they was getting' way above themselves, an' the next thing they think they can do is marry us." "Them" meant black people. In Scout's mind, this doesn't make sense...