If Tom Robinson had been found not guilty, would Harper Lee's To Kill a Mockingbird have been more powerful or less powerful?

In To Kill a Mockingbird, if Tom Robinson had been found not guilty, a completely different message would have been conveyed, making the novel less powerful.

Author Harper Lee uses her book to take a very honest look at racism in the South. Her message was that change needs to be made in order to create true equality for all and that, during the time period in which the book was written, which was 1960, the South was making very tiny little baby steps towards change. Portraying the South as making tiny little baby steps is a very honest reflection of the changes occurring while very honestly stating that many more significant changes still need to be made. Had Robinson been acquitted by the jury, Lee would have been sending a very overly optimistic, dishonest message that significant changes in the South were on the horizon. Lee's much more honest message is far more effective, making it the far more powerful message and storyline.

We best see Lee's message in Miss Maudie's words of wisdom to the children the day immediately after the trial. In an effort to try to cheer the children up, especially Jem, Miss Maudie invites the children over for cake and shares her wisdom. One thing she reminds the children of is the number of people who strove to help Robinson, including the African-American community, Sheriff Heck Tate, and Judge Taylor who purposefully appointed Atticus to defend Robinson rather than Maxwell Green. She further reminds the children that it "was no accident" that Atticus was given the case, whereas the youngest attorney, Maxwell Green, would have automatically been given any cases doomed to lose since he "needed the experience" (Ch. 22). Due to the number of people who were willing to help Robinson, who understood they needed to do all they could to at least try to ensure Robinson had a fair trial, Miss Maudie is able to see that Maycomb is making tiny steps in progress towards creating a more just society. Miss Maudie reflects on the tiny steps Maycomb is making in her following comment to the children:

I waited and waited to see you all come down the sidewalk, and as I waited I thought, Atticus Finch won't win, he can't win, but he's the only man in these parts who can keep a jury out so long in a case like that. And I thought to myself, well, we're making a step--it's just a baby-step, but it's a step. (Ch. 22)

Through Robinson's trial and voices like Miss Maudie, Lee shows us honestly that, while a great deal more progress needs to be made, the South is at least undertaking a tiny bit of progress already.