Aunt Alexandra is depicted as a conservative woman who is prejudiced against black people and supports traditional southern culture. Aunt Alexandra reveals her racial bias by demanding that Atticus fire Calpurnia after she takes Jem and Scout to First Purchase African M. E. Church for Sunday service. Alexandra does not want the children associating with black people, since she views them as inferior and dangerous.
In addition to arguing for Calpurnia's removal, Aunt Alexandra reveals her racial bias by disapproving of Atticus's decision to defend Tom Robinson. Instead of supporting her brother and challenging Maycomb's backward, racist culture, Alexandra talks behind her brother's back and uses racial slurs. In chapter 9, Scout gets into a fight with her cousin Francis Hancock after he repeats Alexandra's racist comments. Francis tells Scout,
Grandma [Aunt Alexandra] says it’s bad enough he lets you all run wild, but now he’s turned out a n----r-lover we’ll never be able to walk the streets of Maycomb agin. He’s ruinin‘ the family, that’s what he’s doin’. (Lee, 85).
Similarly, Scout's teacher Miss Gates also reveals her racial bias by refusing to recognize that her community is prejudiced against black citizens. During a Current Events activity, Miss Gates comments that there is no such thing as prejudice in the United States. Her stance is ridiculous considering the fact that Jim Crow laws discriminate against black people in her hometown. In chapter 26, Scout also recalls overhearing Miss Gates making racist comments when she left the courthouse. Scout tells Jem,
I heard her [Miss Gates] say it’s time somebody taught ’em a lesson, they were gettin‘ way above themselves, an’ the next thing they think they can do is marry us. (Lee, 251).
Overall, Aunt Alexandra and Miss Gates reveal their racial bias by blatantly discriminating against black people, using racial slurs, and disapproving of Atticus's decision to defend Tom Robinson.