In Chapter 9, Scout begins to be teased at school, and later by her cousin Francis, because Atticus is defending a black man. This is another obvious example of the embedded racism in Maycomb at this time. It also foreshadows how significant the trial will be for the town and how difficult it will be for Atticus and his family. Late in the chapter, after Scout's fight with Francis, she overhears Atticus and Uncle Jack talking about the upcoming trial. This is where Atticus overtly talks about the embedded racism and social traditions of Maycomb. Atticus hopes his children will not adopt the traditional Maycomb way of thinking and foresees that they will hear a lot about that way of thinking ("usual disease") as the trial approaches.
You know what’s going to happen as well as I do, Jack, and I hope and pray I can get Jem and Scout through it without bitterness, and most of all, without catching Maycomb’s usual disease. Why reasonable people go stark raving mad when anything involving a Negro comes up, is something I don’t pretend to understand… I just hope that Jem and Scout come to me for their answers instead of listening to the town.
Scout notes that Atticus knew she was listening. She realizes years later Atticus wanted to her to hear him.