How Is The Symbolism Of Tim Johnson More Malignant Than The Symbolism Of The Nutgrass?

The mad dog functions as a symbol of prejudice similar to the nutgrass. Prejudice can occur within a simple subconscious opinion that is formed without much knowledge on the topic or prejudice can occur when a person consciously builds a strong dislike against something or someone that they don’t actually know about. Prejudice could be potentially harmful to the person it is against because if this prejudice is spread, it would cause more people to have prejudice against this person. Miss Maudie's nut grass is a representation of how rumors and gossip in Maycomb County are easily  spread:
“Pull it up, child, pull it up?” She picked up the limp sprout and squeezed her thumb up its tiny stalk. Microscopic grains oozed out. “Why, one sprig of nutgrass could ruin a whole yard. Look here. When it comes fall this dries up and the wind blows it all over  Maycomb County!”(Lee 56)
The analogy of the wind blowing the seeds all over Maycomb County is a representation of the way that prejudice is spread.  The gossip and rumors travel among many people, and, as a result, there are more people experiencing prejudice against someone than there had initially been. Even if the original source of the prejudice is exterminated, the prejudice still remains within all of the people that it was spread to. Similar to the nutgrass, the mad dog is a congenial representation of how prejudice can spread.
The symbolism of Tim Johnson is so malignant and dangerous to the point that the people felt the need to hide to escape the prejudice that the dog represents and could spread. Lee uses the mad dog to display prejudice more malignantly because it is used to display prejudice as a sickness or madness of the brain. Nutgrass can’t be sick or crazy because it is used to display prejudice as a more benign, subconscious judgement. The dog did not have a choice whether it wanted to be the host of rabies or not, it found itself in a situation in which prejudice is involved and the sickness spread to the dog. This also supports the point that prejudice can be a subconscious aspect of thinking.
Heck Tate needed Atticus to exterminate the mad dog. He comes to Atticus because he is known as “One-shot Finch.” Although this is the reason that Heck Tate openly displays to the reader, there is far more symbolism behind this action. Atticus has to kill the mad dog because he is opposed to and immune to all forms unsupported judgement or prejudice. He is the symbol of anti-prejudice so he has to be the one to exterminate the source of the prejudice: "‘Come here,’ he said to Jem. ‘Don't you go near that dog, you understand? Don't go near him, he's just as dangerous dead as alive’” (Lee 111).
This displays that racism is seen like a disease, and the mad dog shows the spread of racism. Atticus is an advocate against racism, while some others of Maycomb are racist. Atticus does not want the town of racist people to reflect or “spread” to Jem and Scout in this case. Even though the main source of the prejudice (Tim Johnson) is dead, the prejudice that had been spread to the other people is still present. The people that this prejudice has affected could then take this prejudice and spread it to others.

Lee, Harper. To Kill a Mockingbird. New York: Harper Perennial Modern Classics, 2006. Print.