As we learn when Atticus discusses the case with his brother, the jury pool he has to select from consists solely of white men, and no white Maycomb man is going to acquit a black man accused of raping a white woman, no matter what the evidence. This would violate the unwritten racist code of the white South, which says that the word of a white is always accepted over the word of a black.

Atticus says that the best he can do is to try to "jar" the jury by presenting a strong case, and that he does. He shows that Tom Robinson, with his crippled arm, could not have raped Mayella as described, and he makes an eloquent closing argument.

Nevertheless, Atticus would agree with the Reverend Sykes, who says,

I ain’t ever seen any jury decide in favor of a colored man over a white man.

Atticus realizes that he would fare better if he could have women like Miss Maudie or blacks in the jury but neither is allowed. He also states that people who might be fairer jurors tend not to want to serve in cases like these, where they feel pressured to publicly declare against their conscience.

While Atticus can't sway the jury enough to get Tom acquitted, he does cause the jurors to deliberate for several hours. Usually, we are told, such a case is decided in a few minutes. Miss Maudie calls this longer deliberation a baby step forward in the life of the town.