Was Darwin a Nazi? Of course not. But did his ideas form a causal nexus via Galton to ideas that would be integrated into Nazi policy? Yes.
Darwin’s racist and pro-eugenics thinking, combined with some implications of his theory that he expressed, laid the groundwork for Hitler’s diabolical outlook.
The book paints Herbert Spencer as the eugenics-championing bad guy and posits that Darwin and Darwinism had little influence on Hitler’s master race ethic.
I have clearly argued in all my works that Hitler was an eclectic thinker who drew on many different intellectual influences — some of them contradictory.