In chapter 24 of To Kill a Mockingbird Ms. Maudie tells Aunt Alexandra, Atticus's prejudiced and haughty sister, that a lot of people are actually rooting for Atticus for having the courage of taking on the task that was bestowed upon him by the judge: To serve as defense attorney to a black man, Tom Robinson, accused of allegedly raping and beating the daughter of Maycomb's most notoriously feral inhabitant, Bob Ewell.
"The handful of people in this town who say that fair play is not marked White Only; the handful of people who say a fair trial is for everybody, not just us; the handful of people with enough humility to think, when they look at a Negro, there but for the Lord's kindness am I."
This is not entirely a 100% support statement in favor of African Americans, but it is a significant statement nevertheless. It shows that Maudie and others can see life from an angle much different than that of the old, tired, and remote city of Maycomb.
Another salient character who demonstrates fairness is Link Deas. The former employer of Tom Robinson stands up in court and announces how he is a witness to the good character of Robinson. Moreover, he creates a job for Helen, Tom's wife and then-widow, and he threatens Bob Ewell with bringing the law down on him if he dares to bully or bother her. He succeeds.
Arguably, we could say that Judge Taylor could also be one of those people. While Taylor appears to be a sore to one's eye, he is nevertheless righteous and serious enough about his job to speak his truths however he sees fit. He demands for people to "shut up" when they speak out of turn in court, and he demonstrates his lack of respect and trust for Bob Ewell when the latter comes to the stand to give testimony. Taylor and Atticus are no different in that they both have to work with what they have---and what they have to work with is a broken system of law that only applies to certain individuals.
Jem, Scout, and Dill- While it is true that the children are raised with the ideas and social stigmas of the time, they can feel the injustice being done to Tom Robinson. Jem even questions if he ever wants to become a lawyer in the future. Scout is in shock and disbelief. Dill, however, hurts more than all others. In fact, Dill is so sensitive at the time of the trial that he lets out his tears and sobs in pain. Out of the three young characters Dill is certainly the one who hurt the most about Tom's case.
Atticus, of course, is the most balanced out and trustworthy character. He does not let any social wave of thought or feeling to affect him. He represents justice in its entirety.
Mr. Underwood, the editor, sole writer, and owner of the Maycomb newspaper is described by Atticus as someone who "despises negroes" and yet played a very active role in protecting both Tom and Atticus against the lynch mob. In fact, he goes as far as to write an editorial that attacked the negative relationship that whites had with blacks, and he even hinted at the possibility that times were finally changing...even in Maycomb.