in chapter 23, what according to atticus is wrong with law and society?

Atticus strongly believes in the goodness of the American system of justice, but he is no idealist.  He says in Ch. 23:  "The one place where a man ought to get a square deal is in a courtroom, be he any color of the rainbow, but people have a way of carrying their resentments right into a jury box." Although the verdict was wrong and unjust, Atticus still says the news wasn't all bad because at least the jury took its time rather than returning a verdict immediately, and that for him was proof that at least one person on the jury was doing some thinking--that being Mr. Cunningham. Thus, for Atticus, it's almost a game of numbers--if the jury had just one more person like Cunningham, the verdict might have gone the other way.  Finally, Atticus seems to think it's a good thing that women were not permitted to sit on juries. He smiles when he says this, but it does indicate some of the issues concerning "southern ladies" in the novel.