Ewell.
One reason being that Atticus is a father to Jem and Scout and is teaching them and the town of maycomb a very important lesson; that people should not be judged by the color of their skin, but by the content of their character.
The next reason is that Atticus has a personal connection to the Tom Robinson case Atticus feels that he “couldn't hold his head in town’’ and “couldn’t represent this country in the legislature” if he did not give this case his all.
As a result, Atticus is taking the Tom Robinson case because of the outcome that may result for himself, his family and the town of