I read that. He said most europeans aren't white but a swarthy complexion. Only the English and Saxons of Germany are white. So even a founder who didn't own slaves was a rambling white supremacists.
Yeah, swarthy was just another way to say black person back in those days. As well as tawny (basically a light skin black).
I can almost understand his disdain for blacks being in control over there (at the time). It's basic human nature to want to see your own people thrive (as he admitted with the bit about partiality).