Oh, I've forgotten to mention: yes, I've read the letter. And a half dozen other things by Dr. King (the whole "I have a dream" speech, the Nobel Prize speech, etc..)

Hannah Arendt is commonly referenced to make a similar point. (I have only read excerpts of The Origin of Totalitarianism.)

I simply disagree that this is what is going on here, as the content should have made plain.