I went looking for an old, old thread about Lovecraft and found this one instead, but I have to say that I have recently been studying H. P. Lovecraft and his contemporaries and can now answer this a bit more thoroughly.
First, I now think the Weird Tales authors are the most concentrated bunch of racists that I can name in literature. I've been reading a lot about them in the last couple years and they were scary. They were "eugenics" racists, who are more-or-less accepted to be the worst kind. So Lovecraft's opinions maybe did not stand out in that company, no.
However, he was an insane racist. And I mean insane, especially during his New York period. Insane to the point where it crippled his relationships and daily life, and was certainly well remarked-upon by the people who knew him. He would make his friends walk in the middle of the street so they wouldn't have to share the sidewalk with what he considered to be inferior races, which included a huge portion of the population that we would now consider "white." He was very, very troubled.
It's difficult to get a grasp on his whole life and I haven't read all his letters yet, but it's now totally safe to say that at least from 1924-1926 HPL was as pure and unmarbled a racist as it is possible to be.
In that sense it was not a fair comparison to Parker, but I don't want to ressurrect an age-old debate, I was just trying to find an old thread where I said "I don't think HPL was a racist as much as he hated everybody equally" and say "Whoa nelly, I was wrong, this is the craziest shit I ever read right here."
The funny thing is that he considered himself a New Deal Democrat. Well, that was after his NYC experiences and I haven't figured out that part of his life yet.