Ted Kennedy's life and political career become derailed in the aftermath of a fatal car accident in 1969 that claims the life of a young campaign strategist, Mary Jo Kopechne.

Jason Clarke
as Ted Kennedy

Kate Mara
as Mary Jo Kopechne

Ed Helms
as Joseph Gargan

Bruce Dern
as Joseph Kennedy

Jim Gaffigan
as Paul Markham

Olivia Thirlby
as Rachel Schiff

Clancy Brown
as Robert McNamara

Taylor Nichols
as Ted Sorensen

John Fiore
as Chief Arena

Gillian Mariner Gordon
as Cricket