The death of Senator Robert Kennedy roils the presidential race. Republican Richard Nixon fights to head off a last-minute challenge from Governor Ronald Reagan of California. Meanwhile, the Democratic Party has lost its most popular candidate and is at war with itself over the Vietnam War. Mayor Richard J. Daley vows to maintain law and order as protesters and politicos converge in Chicago for the Democratic National Convention. The world watches as events inside the convention hall fuel violent clashes in the street. Vice President Hubert Humphrey gains his party's nomination and enters the presidential race as a decided underdog and takes a bold political stance in hopes of reversing his fortunes.