Atticus's moral compass always points to fairness and justice, although justice in that time period is skewed to whites only. He does not judge anyone, at least in front of his children. When his children want to know about something as ugly as what rape is, he gives them the formal definition (which they usually don't understand, but their curiosity is assuaged). He dealt with his children's questions about the racial situation of the time in such a way as to teach, not preach, a lesson.
There is no such thing as equal rights in the novel. Tom Robinson was denied a jury of his peers;there were no black jurors because blacks could not vote at that time. Even with definitive proof that Mayella was beaten by a left-handed person, Tom was found guilty even though his left arm was withered and crippled. Segregation was the norm, both in the court room, neighborhoods, and schools.
Atticus responds to discrimination by volunteering to take Tom Robinson's case. He defended him to the best of his ability, but he was too far ahead of his time to be successful. Even when his life was threatened by the lynch mob, Atticus kept his cool and dealt with the angry men in a civil fashion.
Atticus is truly a moral compass for the town of Maycomb in To Kill a Mockingbird. He is generally regarded as the most honest and down-to-earth man in town, and Miss Maudie tells Scout that he is the one man who acts the same in public as he does inside his home: He treats everyone equally. Tom Robinson's rights certainly seem to be violated when he is accused of rape without a witness and without genetic proof. The fact that the jurors seem to disregard the evidence presented them and pronounce him guilty only magnifies the injustices done to Tom. Atticus attempts to reach the jury by asking them to "do your duty... In the name of God, believe him." He stresses the points that
"... some Negroes lie, some Negroes are immoral, and some Negroes are not to be trusted around women--black or white. But this is a truth that belongs to the human race and to no particular race of men."
Scout also teaches his children to be racially unbiased, hiring Calpurnia and defending her when his sister, Alexandra, wants her fired. Atticus also cautions Scout not to use the word "nigger." "It's common," he tells her.