In Harper Lee's To Kill a Mockingbird, I cannot think of any character that overcomes political injustice. There are several examples of injustice in the novel. Certainly Boo Radley is treated unjustly, but this he suffers at the hands of his family. And Boo never overcomes it, though he does shine for a while.
The only character that I can identify as one who suffers from political injustice is that of Tom Robinson. He is defended by Atticus Finch (one of the novel's main characters) and receives an outstanding defense that he would never have received otherwise—because Atticus is such a morally upright man. He sees no issue of color (for Tom is a black man in a racial community wrongfully accused of raping a white woman). Atticus sees a man—innocent until proven guilty—though he is realistic enough to know that winning this case will be nearly impossible in Maycomb.
While Judge Taylor purposely selects Atticus to defend Tom, knowing that Atticus will do an excellent job, Taylor knows that his town is divided (and not equally) on the question of race. This is the story's political climate. To Kill a Mockingbird is set during the Great Depression. The South has been hit harder than the North because it has not yet recovered from the damage left by the Civil War. There is some tolerance with regard to race, but the majority of people in this small southern town do not represent it.
The prosecution is not concerned about Tom's innocence, for it is apparent early on that the woman (Mayella Ewell) has lied, and was most likely attacked by a left-handed man (her dad)—for Tom Robinson has no use of his left hand. Still, the guilty verdict comes down, though there were some that opposed it—and it was surprising to learn about some of those who did oppose it: unlikely protectors of Tom's rights as a man, rather than as a black man.
Tom does not overcome these obstacles. The idea of imprisonment is too much for him—he snaps; while in the exercise yard of the Enfield Prison Farm (where Tom has been sent), he tries to escape over a barb-wired fence with only one good arm.
They said he just broke into a blind raving charge at the fence and started climbing over...They said if he'd had two good arms he'd of made it, he was moving that fast.
The guards shoot him seventeen times in the back.
The political climate is separated by those liberals who respect the black community, and the conservative, Civil War contingent who believes that blacks are inferior even to white trash, such as Bob Ewell...the man who accuses Tom Robinson, and who most likely beat his daughter, Mayella.
Lee describes Bob Ewell, and the political climate in the story:
All the little man on the witness stand had that made him any better than his nearest neighbors was, that if scrubbed with lye soap in very hot water, his skin was white.