What happens right before the end of the chapter to make the narrator realize the significance of his leadership

At the end of Chapter 20, the narrator is heading back to his office when he notices a police chase. Feeling somewhat responsible for Clifton, he follows in case he will need to pay a fine. Clifton resists the arrest however and fights back. Frozen, the narrator watches Clifton crumple to the ground and realizes that he has been shot. He attempts to help but the cops do not allow him to come closer. Finally they ask him questions about Clifton and tell him that he is dead.

Wandering back to his district, his mind turns over the events and he questions Clifton's motives. He is upset at the unjust killing and feels he must act. Remarking how many men stand outside of history, he is glad to have found a place in the Brotherhood. He still questions if he is right and for the first time notices many of the people around the neighborhoods which he has not been able to help. He realizes that he has been asleep and ignorant.