I’m not sure what portion you’re referring to, but I would say that he uses the rhetorical device of repetition most effectively, as he repeats “I have a dream”.
In the story, "The Cold Equations" by Tom Godwin, Barton the pilot wanted to save Marilyn, the 18 year old girl who was considered an EDS stowaway. He most likely will not succeed because the mission he was carrying out would fail and ultimately kill a lot of people. The girl wanted to meet her brother and talk to him. The story shows events with restriction wherein a hero defies the restriction and tries to save the girl in the process, despite the negative feedback from the government pertaining a law to throw the girl off the ship. In the end, the girl accepted her fate, and after talking with her brother, she was ejected off the ship.
