At the beginning of "The Scarlet Ibis, "how does William Armstrong respond when the narrator pokes his head through the posts of the bed to look at him?

In paragraph 5, president obama remarks: “you know, when trayvon martin was first shot i said that this could have been my son. another way of saying that is trayvon martin could have been me 35 years ago.” how does president obama use rhetoric in this quote to contribute to the overall meaning of his speech?