State the theme of the story as you see it. Support your conclusion by considering the setting, symbols, and the ending.

We might glean several themes from this story. However, one of my personal favorites is that goodness has nothing to do with one's social class; in fact, the existence of social classes can actually victimize some individuals, corrupting them to become "bad" even if they were once good.
The grandmother has a fairly superficial idea of what goodness is.  She seems to believe that her status as "a lady" confers goodness in and of itself; in addition, while she focuses on what is, to her, proof of one's goodness—qualities like having good manners—she lies to her son, manipulates almost everyone in the story, and uses horribly racist and pejorative language to describe African Americans.  Although the grandmother believes that she is uniquely qualified to be "good" because of her status, we see that this woman is elitist, racist, and hypocritical at best.  We might read the grandmother's clothing—her fancy hat, gloves, and dress—as symbolic of her social class and her own belief in her moral superiority.
In the end, we see that the Misfit did not start out with criminal intentions.  He was wrongly accused and convicted of his father's murder, and this—being blamed for something he did not do—ironically put him on the path of criminal behavior.  It seems that people found it easy to blame him as a result of his social class.  However, it is clear that he did not want to kill this family; he only felt that he had to because the grandmother recognized him.  He even tries to comfort her when her son speaks harshly to her.  While he is hardly a "good man" by most people's standards, he is not evil. We can see that there was once, if there is not now, a shred of goodness in him.  He was, in fact, victimized by society—by people just like the grandmother—and this caused him to become the misfit he is now.