In 1973, 43-year-old Philadelphia resident Samuel Byck (Sean Penn) is a down on his luck salesman who desperately wishes to reconcile with his estranged wife Marie (Naomi Watts). A constant moralizer, he states that he stopped working at the tire shop owned by his brother Julius (Michael Wincott) because he would lie to his customers. Believes that society's discrimination affects poor white people just as much as it does African American, he attempts to join the Black Panthers. His dream is to own his own mobile tire sales business in partnership with his best friend, African-American mechanic Bonny (Don Cheadle).