I don't even think it's about the letter. It's the ideology and probably the eugenicist specialty group with the MK Ultra experimental one. In theory they used Hitler as the charismatic front man and were already established, and then worked from within the folds while it was convenient. It's going to be some group already around with the goals and ideals.
Or it's more overt in it being his special Jews. I said it. They worked hidden within as well. And it would have been perfect cover, accounts for Soros success, etc. Fit right in.
Ha, nub confirmation it must be true.