Hannah is writing an essay about the human error that were made during the chicago fire of 1871 several key human errors which is one extraneous detail from this passage

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?