If I were Sam I would side with my father. Violence will only lead to more violence. Nonviolence is a more effective way to get one's point across because it gives the idea of "I know I am right, so I do not have to sink to your level of fighting to get my point across." Stick, Sam's brother, is probably a Black Panther because he thinks nonviolence does not accomplish things fast enough. Sam and Stick's father has more experience and knows that one has to change people's thinking, not strike fear into them.