The setting for the film is late 1950s America, a time during which television was rapidly replacing radio as the most popular entertainment medium. Although Rhodes is coarse and abusive, he possesses a colloquial, on-air charm that quickly endears him to the hearts and minds of rural listeners after Marcia Jeffries (Neal), a small-town radio personality, discovers him in the county jail of the town of Piggott, Arkansas, in northeast Arkansas, and lands him a radio show there. A talent scout invites him to appear on television in Memphis, Tennessee, where Rhodes is introduced to Mel Miller (Matthau), a bookish Vanderbilt University graduate who writes his scripts. However, Rhodes makes a name for himself by insulting his sponsor — to the delight of his adoring audience. Rhodes's sponsor, the "Luffler Mattress" company, is offended but forced to relent in canceling the show when it discovers that Rhodes's antics are actually increasing sales (and that the wife of owner Luffler is a Lonesome Rhodes fan).
An opportunistic "office boy" (portrayed by Anthony Franciosa) lands Rhodes a contract in New York City, where he becomes the national TV spokesman for Vitajex, an innocuous dietary supplement. A frenetic montage of Rhodes's hyperbolic ads for Vitajex is one of the film's most memorable sequences, highlighting the presumed gullibility of the American public to a persuasive con-artist. In the tradition of classical tragedy, Rhodes is undone by his thirst for power and by Jeffries who, despite building his stardom, becomes so fed up that she allows him to expose his contempt for his fans on the air.
As a "Cracker Barrel" broadcast ends, Rhodes is shown, with sound off and an announcer doing a voiceover, smiling and waving to the camera as he speaks contemptuously of his audience. In the control room, Jeffries and the technical staff hear him continue to mock his viewers as "idiots," "morons," "guinea pigs." Fed up with Rhodes's betrayal, aware she helped create the monster, Jeffries pushes slide switches that throw Rhodes's comments on the air. In minutes, furious, betrayed fans who heard the remarks are calling the network. In a symbolic moment, an unaware Rhodes's popularity is shown plummeting as he rides an elevator down following the show. The film ends with a meltdown at Rhodes's penthouse apartment, as Jeffries admits she betrayed him and Matthau predicts his future: that he'll return to the air but it won't be quite as fancy. In the end, he is basically telling Rhodes he is finished. An uncredited Rip Torn is shown at one point as "Barry Mills," the next young Lonesome Rhodes waiting in the wings. The end of the movie has Rhodes voice pathetically calling out "Marsha....don't leave me...".
Interviewed for the DVD release in 2006 and the documentary accompanying the film, Griffith, Neal and Franciosa all express pride in their work in the film, and Schulberg explains the film's origins.
The part about Lonesome Rhodes's being left on the air while he thought he was off the air is taken from an alleged incident in which a children's program host on New York's radio station WOR, Uncle Don Carney, is said to have thought he was off the air. He supposedly said, "This is Uncle Don, saying good night (good night). We're off. Good, that will hold the little bastards." However, there is no proof that this incident ever took place.
The film marked the debut of actress Lee Remick, who plays a teenage baton-twirling champion from Arkansas, one of Rhodes' love interests whom he marries instead of Marcia Jeffries. To underscore the sway of television media in America, Kazan cleverly incorporated several cameos by popular "talking heads," including: Sam Levenson, John Cameron Swayze, Mike Wallace, Earl Wilson, and Walter Winchell.
Some have suggested that the Rhodes character may have been inspired in part by John Henry Faulk, a country comedian who was long blacklisted as a result of the "Red Scare." Schulberg, however, has admitted basing a significant part of the character's facade on that of Will Rogers, adding a distinctively un-Rogers-like level of amorality and cruelty.
Schulberg, in Richard Schickel's 2006 biography of director Elia Kazan, explained that he had met Will Rogers, Jr., who was running for Congress. The younger Rogers told Schulberg how his father socialized with the very establishment types he mocked in his public pronouncements, adding that his father was actually a political reactionary in private life.
Since Godfrey was involved in similar controversies based on the press's seeing the difference between his amiable on-air personality and his cold, controlling offstage ferocity, many parallels were drawn between the two.
Two cast members had genuine ties to the country music field. Big Jeff Bess, who portrayed the Sheriff, was a Nashville-based country music performer on radio station WLAC there, leading a group called "Big Jeff and His Radio Playboys," who recorded for Dot Records and included guitarist Grady Martin. Bess was, for a time, the husband of Tootsie Bess, longtime owner of Nashville's famous downtown bar Tootsie's Orchid Lounge, a hangout for country entertainers.