How does being an outsider or outcast affect a person's ability to change society, as seen in Harper Lee's To Kill a Mockingbird?

In Harper Lee's To Kill a Mockingbird, we see that being an outsider does not significantly impact one's ability to change society; however, it can create a tiny bit of change.

Atticus Finch is one example of an outsider in the novel. He is considered an outsider because he goes against the grain of society by deciding to put his all into defending Tom Robinson. Atticus lives in a very racist, segregated society, whose white members automatically believe that the African American members of society are born morally and intellectually inferior. We see Maycomb society's belief in African American moral inferiority expressed in every racist remark all throughout the book. We particularly see the idea of moral inferiority expressed by Mrs. Farrow at Aunt Alexandra's Missionary Society meeting held just after Tom Robinson's trial. During a conversation about how much the African Americans have been grumbling since Robinson was found guilty, Mrs. Farrow recites the following comment she made to Brother Hutson earlier:

Looks like we're fighting a losing battle, a losing battle. . . . it doesn't matter to 'em one bit. We can educate 'em till we're blue in the face, we can try till we drop to make Christians out of 'em, but there's no lady safe in her bed these nights. (Ch. 24)

However, despite such racist beliefs as those expressed by Mrs Farrow, Atticus is able to put himself inside the shoes of all his fellow human beings and see that most people are genuinely good human beings. Because of his compassion for humanity, he is able to see that not enough evidence exists in Robinson's case to legitimately convict him beyond a reasonable doubt; Atticus is also able to see that all circumstantial evidence points to Robinson's innocence, not his guilt. Since Atticus is open-minded and compassionate, not racist, he is able to see it is his moral duty to put his all into defending Robinson, despite what the rest of Maycomb's society thinks.

However, sadly, Atticus's defense does not yield much success. Robinson is still declared guilty by the racist all-white jury, despite all evidence to the contrary. Regardless of the ultimately disappointing outcome, Miss Maudie is one to note the impact Atticus was able to have on the jury, stating that "he's the only man in these parts who can keep a jury out so long in a case like that" (Ch. 22). Miss Maudie further notes the impact Atticus had by stating, "[W]e're making a step—it's just a baby-step, but it's a step" (Ch. 22). In other words, though Atticus's actions as an outsider did not have a significant impact, his actions at least had a tiny impact, and that tiny impact is enough to serve as a catalyst for greater changes to come.