What is the theme of "Rumble Fish" by S.E. Hinton?

There are a few major themes. They are: fate, alienation/abondonment, hopelessness, and poverty.

The main character has to grapple with a sense that his life is hopeless and that nothing can change that.

What quote can be used to relate to the theme of the book, Rumble Fish?

The primary themes of the book relate to alienation and hopelessness - the sense that there is no escape from the forces which determine the life of the main character, Rusty James.  Some quotes which relate to these themes include:

"I didn't much want to talk about the good old days.  I didn't even remember them" (Chapter 1 - RJ).

"I don't see any sense in thinking about things far off in the future" (Chapter 2 - RJ).

"I threw my cigarette butt into the river.  It was so full of trash that a little more wasn't going to hurt it any" (Chapter 2 - RJ).

""Kid...I never got past the river" (Chapter 3 - Motorcycle Boy).

"When the hell did you start expecting anything to be fair?" (Chapter 3 - Motorcycle Boy).

"I decided he must still be worrying about his mother.  I couldn't remember mine, so I didn't know how he felt" (Chapter 4 - RJ).

"I couldn't remember how crying felt..." (Chapter 6 - RJ).

"...Those guys would have followed you anywhere...most of them still would"..."It would be great...if I could think of somewhere to go" (Chapter 6 - RJ and Motorcycle Boy).

"Is this real?  Is this real?"..."(he) seemd terrified when he realized he wasn't dreaming" (Chapter 7 - Steve and RJ).

"He didn't belong - anywhere - and what was worse, he didn't want to" (Chapter 8 - RJ).

What are the key plot points in Rumble Fish by S. E. Hinton?

Susan E. Hinton's teen novel, Rumble Fish, deals with the gang violence that rules the life of young Rusty-James and, previously, his older brother, the Motorcycle Boy. The former leader of a Tulsa, Oklahoma gang, the Motorcycle Boy issues an edict that the violence must stop before he escapes the city by heading to California. However, Rusty-James--now the leader of a gang himself--has decided that fighting is a necessary evil between rival gangs. Once again coming to his brother's rescue, the Motorcycle Boy's sudden return to Tulsa comes just in time to save Rusty-James from severe injuries. The boys come from a broken home, their father is an alcoholic, and their mother has herself escaped to California. Rusty-James reveres his brother, but the Motorcyle Boy wants no part of his brother's adulation. Things go bad for both boys in the end: The Motorcycle Boy is killed by a policeman's bullet, and Rusty-James heads to a reformatory. The story ends with the now-free Rusty-James living in California, attempting to forget his past life.