It seems to me that even if you went through time and killed Hitler there would have been another one. As if there had to be a Hitler since all elements were present: economical despair, anti semitism, Christian supremacy, Vatican... I mean you had similar autocrats in Italy and Spain and killing Jews was always business as usual in Europe only this time it was recorded on video so people could really rewatch it and reassess what they've done.
teachings of the Bible are so muddled and self-contradictory that it was possible for Christians to happily burn heretics alive for five long centuries. It was even possible for the most venerated patriarchs of the Church, like St. Augustine and St. Thomas Aquinas, to conclude that heretics should be tortured (Augustine) or killed outright (Aquinas). Martin Luther and John Calvin advocated the wholesale murder of heretics, apostates, Jews, and witches. - Sam Harris, "Letter To A Christian Nation"
