For a long time, I thought he and Joseph Campbell were the same person (as in "the mentor of Asimov, the one with the hero's journey").
Extra Credit in their series on the history of science fiction did a rather good episode on his influence, for good and for bad: https://youtu.be/Ctpvd2VvukQ
The article barely touches on Campbell's racism, bringing it up only in the context of being an "angry old man" in the 1960s.
To give another example, he rejected a story by Samuel R. Delany in 1967 - https://www.nyrsf.com/racism-and-science-fiction-.html :
> ... with a note and phone call to my agent explaining that he didn’t feel his readership would be able to relate to a black main character. That was one of my first direct encounters, as a professional writer, with the slippery and always commercialized form of liberal American prejudice: Campbell had nothing against my being black, you understand. (There reputedly exists a letter from him to horror writer Dean Koontz, from only a year or two later, in which Campbell argues in all seriousness that a technologically advanced black civilization is a social and a biological impossibility. . . .). No, perish the thought! Surely there was not a prejudiced bone in his body! It’s just that I had, by pure happenstance, chosen to write about someone whose mother was from Senegal (and whose father was from Norway), and it was the poor benighted readers, out there in America’s heartland, who, in 1967, would be too upset. . . .
But he was a racist all his life. You ever wonder why the 'Golden Age' SF almost all has white men as the main character, with humans almost always winning over aliens? It's in part because his big influence on SF caused his racism to permeate the stories I read and enjoyed as a kid.
Here's a paraphrase from Asimov (Campbell, btw, felt that Jews were a superior species of human), quoted at https://andrewhickey.info/2017/08/09/the-prometheans-wheels-... :
> Campbell’s racist views had a stifling effect on his writers even in the 1940s – Asimov said that one reason his stories never featured aliens was because Campbell would always insist that humans were superior to aliens, because he couldn’t cope with a worldview where white American men weren’t the best, so the left-leaning Asimov just didn’t write stories with aliens in, to avoid the problem.
Heinlein's 1941 "Sixth Column" was an idea originally developed by Campbell. Quoting https://en.wikipedia.org/wiki/Robert_A._Heinlein#Race :
> The idea for the story was pushed on Heinlein by editor John W. Campbell, and Heinlein wrote later that he had "had to re-slant it to remove racist aspects of the original story line" and that he did not "consider it to be an artistic success."
As a avid reader, some would say obsessive, I have never respected the work of John Campbell. His science fiction simply feels naive and implausible, composed of technological awe that would not exist in a real situation. His writing always struck me as childish, and the members of my book club (during elementary, where I was the only kid in a club of adults) warned me of his racism, so it was easy ti disregard him. After all, there is much better SF than his kiddie wow.
For people in the EU, who are blocked by latimes.com, the content is available on archive.is: http://archive.is/FTAz5