Steve Bannon is simply a White Supremacist, there isn't really any argumentation to speak of.
No, I don't think he is, in that he doesn't want whites to lord it over non-whites. What he wants, as I understand it, is for different races and cultures to live in different societies/countries.
Richard B. Spencer is a leading figure in the American Alt-Right (he even created the name). Here's a section from the beginning of his Wikipedia article:
Richard Bertrand Spencer (born May 11, 1978) is a noted American white supremacist. He is president of the National Policy Institute, a white nationalist think tank, and Washington Summit Publishers, an independent publishing firm. Spencer has stated that he rejects the description of white supremacist, and describes himself as an identitarian. He advocates for a white homeland for a "dispossessed white race" and calls for "peaceful ethnic cleansing" to halt the "deconstruction" of European culture.
I'm not sure what a "peaceful ethnic cleansing" would look like, and I don't think I want to find out.
Peaceful for himself I suppose. He'd like to be nice and cozy, miles from the action, while it's being carried out.
The more that lad get's slapped about the place, the better I feel.
It's clearly impossible.
Then of course they bring up "white genocide" and are staunch antimiscegenationists.