Another potential character to look at is Maudie Atkinson. As the trial draws to its close, Miss Maudie tells Scout that a lot more people in Maycomb supported Atticus than perhaps she realized. Miss Maudie herself, a lady of the old South, even admits that she wanted to see the trial end successfully, with the acquittal of Tom Robinson, and she knew many others who did as well.
This statement of opinion is a vast departure from the segregated mindset of Maycomb County on the whole, and displays a willingness and desire for social change on a grander level than the trial of Tom Robinson would permit.
One character that you might look to is Walter Cunningham. He comes to the jail that night with violence on his mind, but after Scout humanizes him, he leaves, ashamed. That could prompt him to want to change his ways; his shame at his violent intentions might drive him to bettering himself. In fact, Atticus hints around that it might have been a Cunningham that
"took considerable wearing down-in the beginning he was rarin' for an outright acquittal".
Now, this probably wasn't the same Walter Cunningham that stood outside the jail, but, there is change brewing in the Cunningham clan, hat was brought out by Bob's disgraceful lies, and who knows how Walter influenced it, or will be influenced by it in the future.
Another person that might subconsciously want change is Mayella Ewell herself. She lives in squallor and poverty, but Lee mentions specifically that she was growing beautiful red flowers on their trashed property. Atticus brings out the fact that she was pretty lonely. Bob reminded her over and over of her station in life, but she was trying. So, somewhere, deep down, she wanted to get out of there, and better her circumstances. Unfortunately, her attempts at companionship were misguided and led to Tom's arrest. All of that stemmed from her subconscious desire to better her situation.
Then, consider Boo Radley. He had made attempts to befriend Jem and Scout throughout the novel, but was always shut down by his family. He wants to change; his gifts and tokens in the trees, and his laughter at their games indicated his desire to reach out, for the first time in 30 years. But, it took Bob Ewell's attack to get him to actually get out of the house and take a proactive role in their lives. The desire was there before, but Bob's attack brought Boo out, and made him a concrete part of their lives.
I hope those thoughts help a bit; it's an interesting question that you have there. Good luck!