Each member of Bobby's group is considered an outcast because they do not conform to the expectations of society. In middle school, many students try desperately to fit in so as not to draw attention to themselves. Bobby's group are all outsiders in middle school for different reasons.
Addie is tall and intelligent, two qualities that cause her to stand out from the herd. However, her choice to refuse to stand and say the pledge of allegiance with her classmates is what initially draws the scrutiny of the student body. Just being a student sitting while all the other students are standing creates an image of an outcast. Her decision to create a third political party, The No-Name Party, to run in school elections further cements her position as an outcast.
Skeezie is an outcast because of how he dresses. Instead of choosing to wear the same clothes from the same stores that all the other students at school are wearing, Skeezie expresses his individuality through his clothing choices by dressing like a greaser from the fifties. He faces ridicule and name-calling from the other students because of this choice.
Joe is an outcast because of his sexuality. He is gay and is often taunted and teased for being more feminine than his classmates deem acceptable. He arrives at school one day to find "fagot" written on his locker. Though the word is misspelled, Joe believes he knows who wrote the slur. When he confronts a classmate, Kevin Hennessey, who has consistently called him "faggot," Kevin denies writing it on Joe's locker.
Finally, Bobby is an outcast because of his weight. He has been overweight since elementary school, and students have been calling him names such as "Pork-Chop" and "Fluff" to ridicule his weight.
All four students are also outcasts because instead of conforming to the norms of middle school and accepting the name-calling and ridicule of classmates, the Gang of Five decide to fight back. They form a political party to run in the school elections and are determined to change how they are perceived by their classmates.