what does Atticus tell scout she will have a tough time because?

 A boy at school, Cecil Jacobs, teases Scout, saying that her father "defends niggers". Scout will not accept insults about her father and fights Cecil. Later Atticus says that things are going to get tougher for her as the trial grows closer. People in Maycomb are entrenched in their bigotry and their ignorance will spill out onto her and Jem. Scout will have to be more tolerant of ignorance.