Henry Fonda as Robert Leffingwell

Charles Laughton as Senator Seabright Cooley

Don Murray as Senator Brigham Anderson

Walter Pidgeon as Senate Majority Leader

Peter Lawford as Senator Lafe Smith

Gene Tierney as Dolly Harrison

Franchot Tone as The President

Lew Ayres as The Vice President

Burgess Meredith as Herbert Gelman

Eddie Hodges as Johnny Leffingwell

Paul Ford as Senator Stanley Danta

George Grizzard as Senator Fred van Ackerman

Inga Swenson as Ellen Anderson

Frank Sinatra as Self (voice)

Edward Andrews as Senator Orrin Knox

Paul McGrath as Hardiman Fletcher

Will Geer as Senate Minority Leader

Betty White as Senator Bessie Adams

Tom Helmore as British Ambassador

Rene Paul as French Ambassador

Paul Stevens as Louis Newborn

Russ Brown as Night Watchman Mike

Malcolm Atterbury as Senator Tom August

Janet Jane Carty as Pidge Anderson

Hilary Eaves as Lady Maudulayne

Michele Montau as Celestine Barre

J. Edward McKinley as Senator Powell Hanson

Bill Quinn as Senator Paul Hendershot

Tiki Santos as Senator Kanaho

Raoul De Leon as Senator Velez

Chet Stratton as Rev. Carney Birch

Larry Tucker as Manuel

Betty Murray as Senator Lafe Smith's Girlfriend

John Granger as Ray Shaff

Sid Gould as Bartender

Meyer Davis as Orchestra Conductor

Irv Kupcinet as Journalist #1

Robert C. Wilson as Journalist #2

Alan Emory as Journalist #3

Jesse Stearns Buscher as Journalist #4

Milton Berliner as Journalist #5

Allan W. Cromley as Journalist #6

William Knighton as WHCA President

Guy M. Gillette as Senator Harper

Henry Fountain Ashurst as Senator McCafferty

Raj Mallick as Indian Ambassador

Leon Alton as Senator (uncredited)

Walter Bacon as Senator (uncredited)

Joe Baird as Senator (uncredited)

Eddie Baker as Senator (uncredited)

Brandon Beach as Senator (uncredited)

Mario Cimino as Senator (uncredited)

Roger Clark as Senator (uncredited)

Paul Cristo as Senate Gallery Spectator (uncredited)

Harry Denny as Senator (uncredited)

George DeNormand as Senator (uncredited)

George Ford as Senator (uncredited)

Cay Forester as President's Secretary (uncredited)

Bobby Gilbert as Senator (uncredited)

Polly Guggenheim as Washington Socialite (uncredited)

Clive Halliday as Senator (uncredited)

Helen Hardin as Washington Socialite (uncredited)

Henry Jackson as Drink Refuser (uncredited)

Virgil Johansen as Senator (uncredited)

Kenner G. Kemp as Senate Chamber Reporter (uncredited)

Joseph La Cava as Senator (uncredited)

Evelyn Lincoln as Washington Party Guest (uncredited)

Al McGranary as Senator (uncredited)

William Meader as Senator (uncredited)

Harold Miller as Senate Official (uncredited)

Sol Murgi as Senator (uncredited)

Norman Papson as Gay Bar Patron (uncredited)

Charles Perry as Senate Gallery Spectator (uncredited)

Paul Power as Senator (uncredited)

Walter Reed as Senate Staff Clerk (uncredited)

Leoda Richards as Senator (uncredited)

Clark Ross as Senator (uncredited)

John Roy as Reporter (uncredited)

Carlisle Runge as Washington Party Guest (uncredited)

Dick Ryan as Senator (uncredited)

Jeffrey Sayre as Senate Staff Clerk (uncredited)

Louis Scheyven as Washington Party Guest (uncredited)

Bernard Sell as Senator (uncredited)

Stephen Soldi as Senate Gallery Spectator (uncredited)

Marion Lloyd Stearns White as Washington Party Guest (uncredited)

Hal Taggart as Senator (uncredited)

Wayne Tucker as Journalist (uncredited)

Harty Wadsworth as Washington Party Guest (uncredited)

Jerry Wadsworth as Washington Party Guest (uncredited)

Byron White as Washington Party Guest (uncredited)