No one who lives in the United States can be considered an "outsider."
These are brilliant, specific arguments:
"influenced by the view which argues against 'outsiders coming in'" (paragraph 1). King writes, "We are caught in an inescapable network of mutuality, tied in a single garment of destiny" (paragraph 4).
King is all about Christian fellowship and harmony among people. He is angry about the injustice, but he is calling for "brotherhood" and peace.
So... as you read, you will see that he achnowledges certain ways of thinking -- within the church or within Alabama -- and then he says something thoughtful that makes you stop to reconsider. These are the specific arguments.
Enjoy it!! This is one of his best.