Your writing provides a solid start in discussing the theme of racism in To Kill a Mockingbird. Here’s a revised version to enhance clarity, coherence, and flow:
In To Kill a Mockingbird, the residents of Maycomb oppose Atticus Finch's decisions largely due to their personal prejudices against Black people. For example, when Scout Finch gets into a fight with her classmate Cecil Jacobs, it stems from Cecil's announcement at school that her father is defending a Black man, referring to him with a racial slur. Scout is understandably angered by this insult, demonstrating how deeply racism is ingrained in the community. This incident illustrates that many people resort to using derogatory language to express their hatred and maintain their sense of superiority.
Moreover, when Atticus's sister, Alexandra, visits, she expresses strong disapproval of his decision to defend a Black man. Her focus is on preserving family honor and adhering to traditional social values, suggesting that she believes Atticus's actions threaten their social standing in a prejudiced society. Alexandra's stance reflects the broader societal expectations in Maycomb, where racial discrimination is woven into the fabric of social relations.
This revision maintains the ideas you've presented while improving clarity and flow. Consider expanding on some points or adding more examples to further illustrate the societal nuances depicted in the novel.