In To Kill a Mockingbird, Harper Lee addressed the issue of prejudice many times. Lee certainly chose to use her portrayals of the Ewells, especially Bob Ewell, and Tom Robinson to discredit racial stereotypes, such as those that suggested that African-Americans were dirty, ignorant, and basically worthless (think welfare). It was especially significant that Lee chose to address this issue at a time when aspects of racism and equality were in the forefront of social and political agendas.
Lee presents Bob Ewell as "white trash" in order to illustrate the point that race is no indicator of worth or lack of such. Bob Ewell is a white man who chooses to live in filth, neglect and abuse his children, and act brutish in virtually every aspect of his life. The fact that Ewell is completely ignorant as to what he says and does that is so amusing only serves to heighten the reader's awareness that, despite his race, Ewell apparently embodies no positive traits.
Ewell's use of speech that is far from correct or appropriate strengthens the reader's perception of his being ignorant and classless, despite the fact that he seems to fail to notice this. When Ewell is describing the events that took place the night of Mayella's attack, his speech is poor at best.
"Well, I run around the house to get in, but he run out the front door just ahead of me. I sawed who he was, all right. I was too distracted about Mayella to run after'im. I run in the house and she was lyin' on the floor squallin'--"
Later, Ewell truly demonstrates his ignorance when Mr. Gilmer asks him if he is ambidextrous.
"I most positively am not, I can use one hand good as the other. One hand good as the other," he added, glaring at the defense table.
By presenting Ewell as an uneducated, irresponsible, and ignorant person, Harper Lee shows that race cannot be blamed for a person's character and performance as a member of a family or society.
In addition, Lee portrays Tom Robinson as a gentle, kind man with common sense, integrity, and general good character. While Robinson's speech is not perfectly correct, it is appropriate and lacks the glaring mistakes evident in Ewell's speech. Robinson also shows respect for those around him, while Ewell does not. When Robinson confesses that he has been inside the Ewell's fence on many occasions, Atticus Finch asks him whether he was paid for his work. Robinson's kind and generous nature is again made apparent through his answer.
"No suh, not after she offered me a nickel the first time. I was glad to do it, Mr. Ewell didn't seem to help her none, and neither did the chillun, and I knowed she didn't have no nickels to spare."
Even when Robinson knows that he is in a potentially dangerous situation, he refuses to harm Mayella, unlike her own father.
..."She reached up an' kissed me 'side of th' face. She says she never kissed a grown man before an' she might as well kiss a nigger. She says what her papa do to her don't count. She says, 'Kiss me back, nigger.' I say Miss Mayella lemme outa here an' tried to run but she got her back to the door an' I'da had to push her. i didn't wanta harm her, Mr. Finch an' I say lemme pass, but just when I say it Mr. Ewell yonder hollerin' through th' window."
By giving Bob Ewell characteristics common to stereotypes of African-Americans and presenting Tom Robinson with character thought to be common to white people, Harper Lee clearly subverts racial stereotypes.