https://www.reddit.com/r/AskHistorians/comments/5h6r24/i_have_a_question_about_german_antisemitism/day5m0g/

/u/kieslowskifan talks about the history of anti semitism in germany

https://www.reddit.com/r/AskHistorians/comments/66x6js/did_hitler_exploit_an_already_existing_genocidal/

https://www.reddit.com/r/AskHistorians/comments/4b7lgq/how_did_hitler_get_the_idea_that_there_was_a/

/u/commiespaceinvader also has great answers here