The Ewells, "the disgrace of Maycomb for three generations," are crude and dishonest, clearly out of their element in a public courtroom. Bob is smug and cocky, and his antagonistic remark about Tom,
"... that black nigger yonder ruttin' on my Mayella,"
turned the courtroom into a circus. Bob seemed to enjoy the chaos that he had created, and all
... that made him any better than his nearest neighbors (the Negroes in the Quarters) was, that if scrubbed with lye soap in very hot water, he was white.
Mayella is shy and withdrawn, unused to any social contact whatsever. She mistakes Atticus' mannerly politeness, when he calls her "ma'am" and "Miss Mayella," as sarcasm. Mayella seems so bewildered that Scout asks Jem "if she has good sense." Although she is a character deserving of some sympathy, it is hard for the reader to absolve her from her deliberate lies about Tom, perhaps the only man who has ever responded to her in a friendly manner.
Tom comes across as
"... a quiet, respectable humble Negro who had the unmitigated temerity to ' feel sorry ' for a white woman."
He truthfully and respectfully answers every question, remaining calm even when the prosecutor repeatedly calls him "boy." He is an innocent black man who made the mistake of entering a white man's home--even worse, a Ewell's shack--with the good intention of helping a needy neighbor. He realizes his predicament is serious, but he explains that he ran because he was "scared I'd be in court, just like I am now." But none of this matters: His skin is black, and the Ewells are white, and the jury will not "take Tom Robinson's word against the Ewells."