"Race and Human Evolution" by Wolpoff and Caspari also gave the racial ideology background which helps to see how Hitler just naturally filled the role expected of someone like him.
Jordan Peterson and Stephen Hicks have touched upon this, but it does seem like ideologies have a life of their own, sort of like a representation of a thought center, and all they need are 'willing' participants to act as vehicles to act out those ideas in physical reality. Kind of like how bacteria make up a large portion of who we are and in many ways shape our behaviour, moods and emotions, and in the Work, parsing out what's real and 'I' as opposed to what constitutes programs or something else acting through us. It really brings home the point of what the C's said to Terry about the battle not being for us, but through us. We really have to be careful what we allow into our 'fields' of perception as well as what we choose to believe or don't believe and whether they constitute lies or the truth - both about ourselves and the world around us.