or the seminal essay "Supernatural Horror in Literature."

I have read this before but was just rereading again and it I had forgotten that it includes quite the impressive case of how Lovecraft manages to view seemingly everything through the lens of his peculiar version of racialism:

Much of the power of Western horror-lore was undoubtedly due to the hidden but often suspected presence of a hideous cult of nocturnal worshippers whose strange customs--descended from pre-Aryan and pre-agricultural times when a squat race of Mongoloids roved over Europe with their flocks and herds--were rooted in the most revolting fertility-rites of immemorial antiquity.

And slightly later we have:

in the Latin races there is a touch of basic rationality which denies to even their strangest superstitions many of the overtones of glamour so characteristic of our own forest-born and ice-fostered whisper infs.

Why do people bring up racism in regards to Lovecraft? Dude could not stop bringing it up himself, even in the most seemingly irrelevant contexts.

I get that these views were not unique to Lovecraft, but neither were they remotely universal or "normal" among white writers of his time--The Great Gatsby satirizes views like these. Lovecraft feels like the equivalent of the people who pass around stories about "White genocide" and "Irish slaves" today. Not unique, but more racist than their racist times.