Whitaker Chambers. Oh wait.
I once read a psychologlical profile of Whittaker Chambers in, of all places, a long, detailed biography of the most fascinating man of the twentieth century, Henry R. Luce.
It didn't excuse people turning their coat, but it explained it.
Whittaker Chambers was from a rather modest background, and while he was a member of the Communist Party, he was hobnobbing with the Ivy League elite, the academic elite, affluent white liberals, the catered class.
He did yeoman's work for them as a Communist, but sooner or later it dawned upon him that no matter how good he was, he was never going to be accepted by the Alger Hiss-Owen Lattimore Country Club set.
And so he went to the other side, more accepting of diversity and utterly dismissive of "background" as a gauge of character.
There's a lesson in this.