Atticus Finch's actions and comments that are important?

Atticus's decision to defend a black man, Tom Robinson, on the charge of raping a white girl, Mayella Ewell, drives the narrative forward. Atticus explains to his children that he is deffending Tom, “For a number of reasons,” said Atticus. “The main one is, if I didn’t I couldn’t hold up my head in town, I couldn’t represent this county in the legislature, I couldn’t even tell you or Jem not to do something again.”