MLK

I believe that MLK was writing to the general public. Even though he had an implicit audience of those who have power and an influence over people for a "better good", he was writing for a variety of audiences. He was writing to these in little power too, so that they would do something...anything. Sitting back and not doing anything is worse than doing something and being denied access or rights.  Being denied leaves room for improvement and the clergy were bound to listen to this letter and its proclaimed  determined statements.