To clarify, he was absolutely racist with really reactionary views. He wasn't a Nazi.
I'm not defending him, but I also think it's worth being clear about who was and wasn't a Nazi when discussing those alive during the Nazi Party.
For anyone curious, this letter (sorry for linking that site on lemmy, best source i could find) has him discussing Hitler in 1933. It's far more positive than I'd ever defend, but it's also pretty clear he's not a Nazi. He saw Nazism as the lesser of two evils compared to Bolshevism. I think that's a fucking bad take, but I don't think someone who says
"Still—don’t get my wrong. I’m not saying that Schön[e] Adolf is anything more than a lesser evil... When the Germans can get another leader, & emerge from the present period of arbitrary fanaticism, his usefulness will be over."
is a Nazi. He was just a good ol' New England reactionary racist.
This video essay also has some really great insight into discussing the reactionary nature of Lovecraft from a leftist standpoint while still recognizing his literary contributions.