What does this quote mean? "People have a way of carrying their resentments right into a jury box...."
Atticus means that a racist will be racist in the jury box.
This quote is Atticus’s explanation of why the jury convicted Tom Robinson even though Jem thinks Atticus proved he was innocent. Atticus says that people are convicted on circumstantial evidence all of the time. The main reason Tom Robinson was convicted was his race.
When Atticus says that people carry their resentments into the jury box, he means that people on a jury cannot always forget who they are. If they are racist, they are going to be racist during the trial. The jury was just not able to overcome the fact that Tom Robinson was black.
“There’s nothing more sickening to me than a lowgrade white man who’ll take advantage of a Negro’s ignorance. Don’t fool yourselves—it’s all adding up and one of these days we’re going to pay the bill for it. I hope it’s not in you children’s time.” (Ch. 23)
Atticus is trying to explain to Jem why racism affects every aspect of life. He doesn’t approve of this. He was hoping that, as he said in his closing statement, a courtroom could be a place where everyone is equal regardless of race.
Atticus does tell Jem that one of the Cunninghams was in favor of acquitting Tom Robinson. This surprises Jem, because he was one of the men in the angry mob who tried to attack Robinson.
“Golly Moses,” Jem said reverently. “One minute they’re tryin‘ to kill him and the next they’re tryin’ to turn him loose… I’ll never understand those folks as long as I live.” (Ch. 23)
Atticus tells Jem that the Cunninghams are good and proud people. He says it takes “a thunderbolt plus another Cunningham to make one of them change his mind” and that if there had been two Cunninghams on the jury they would have hung it.