In To Kill a Mockingbird how are Jem and Dill affected by racism?

and Dill are
shocked and disillusioned by the way Tom Robinson is treated during the trial. First, Dill
becomes emotionally overwhelmed by the way Mr. Gilmer, the prosecuting attorney, speaks so
condescendingly and disrespectfully to Tom. He becomes so upset that he cries during the trial;
so Jem hastake Dill outside to calm down. Once they get outside, Scout tries to explain that
attorneys have to talk that way because that is their job. Scout even says something very
insensitive: "Well, Dill, after all he's just a Negro." This shows that Scout does not
have the mature perspective that Dill has, yet. Dill responds to her by saying the
following:

"I don't care one speck. It ain't right,
somehow it ain't right to do 'em that way. Hasn't anybody got any business talkin' like that--it
just makes me sick" (199).

Clearly, Dill understands
the nastiness behind the way Mr. Gilmer was speaking to Tom Robinson, but he can't articulate
it. Dill feels great empathy for Tom because of the racism and prejudice being displayed. He is
sickened and cries because of how much it frustrates him to see Tom treated so
poorly. 

Jem, on the other hand, understands the ways of attorneys and
trials; so, he puts up with Mr. Gilmer's attitude for longer than Dill can. With faith in the
justice system, and in 's arguments for the defense, Jem holds onto hope for Tom's acquittal up
until the disappointing verdict is read. This is when Jem breaks down and cries. Atticus does
his best to explain the nature of racism afterwards--although he doesn't use that word. He tells
Jem that a jury of white men simply could not acquit Tom because of a long-standing tradition of
prejudice and racism in the South. Jem has such a difficult time accepting this that he never
wants to talk about the trial again. For example, when Scout wants to understand the difference
between how Hitler treats Jews and the way her teacher, Miss Gates, spoke about African
Americans after the trial, Jem explodes as follows:

"Jem was suddenly furious. He leaped off the bed, grabbed me by the collar and
shook me. 'I never wanta hear about that courthouse again, ever, ever, you hear me? You hear me?
Don't you ever say one word to me about it again, you hear? Now go on!'" (247).

Even months after the trial, Jem still isn't ready to face the
facts of racism and prejudice--or at least he can't talk about them.