What are Jem's views about the trial?
As the trial progresses, Jem becomes more and more confident in the possibility that Tom Robinson will be acquitted. After Atticus' final speech before the jury, Jem reassures Reverend Sykes that Tom will very likely be found innocent; he tells the minister not to "fret."
For his part, Reverend Sykes cautions Jem against over-confidence; he asserts that he's never seen a jury "decide in favor of a colored man over a white man." Despite the minister's warnings, Jem remains confident that his father's logical arguments will win the day. So, when the jury unanimously pronounces Tom Robinson guilty, Jem is shocked, dismayed, and angry. Scout relates that Jem's face is "streaked with angry tears" as the siblings make their way out of the courtroom.
At home, Jem tearfully asks Atticus how a jury could have ignored the clear evidence before them and pronounced a guilty verdict. Atticus answers:
“I don’t know, but they did it. They’ve done it before and they did it tonight and they’ll do it again and when they do it—seems that only children weep..."
The morning after the trial, Atticus tries to comfort Jem by mentioning the possibility of an appeal. Later, Miss Maudie assures Jem that, although Atticus didn't win the case, he managed to keep the jury out longer than anyone had anticipated. Miss Maudie tells Jem that Atticus' small victory is a "baby-step" in the right direction for Maycomb.
So, Jem is initially hopeful about the trial, but he later changes his view about it after the verdict against Tom is announced. Like Atticus, Jem had hoped that justice would prevail. When Tom was pronounced guilty, however, Jem began to question the efficacy of Maycomb's court system. He became disillusioned and angry that prejudice had ruled the day.