this is a good expansion on the points i've been making and struggling to source, because they've been swept under the rug. if you look up any of these people on wikipedia, you'll see what they were really like. but, if you focus your googling on anything written about racism in the populist movement, you'll just get hints. that centralized discussion seems to rarely get published.
so, this is some kid's grad thesis, but he does the work and puts it all together. i really can't remember where i read about this previously, and would tell you if i did remember, but it's the kinds of things i remember reading about before, so it's a good representation of what i'm magic-wand non-sourcing from. consider this my source.