How is Miss Gates a hypocrite during her lesson about the Jews?

Miss Gates' lesson is about Hitler and the persecution of the Jews. During the lesson, she takes care to note that people here (America) don't believe or participate in persecution. Scout find Miss Gates a complete hypocrite based upon her comment at Tom Robinson's trial.

I heard her say it’s time somebody taught ’em a lesson, they were gettin‘ way above themselves, an’ the next thing they think they can do is marry us. Jem, how can you hate Hitler so bad an‘ then turn around and be ugly about folks right at home—”