Preston Foster plays James Ellsworth 'Jimmy' Hughes, a carefree socialite who can’t resist a bold dare. After a drunken night ends with him misappropriating a milk truck, he is awakened by his gentleman’s gentleman Herbert Mundin as Jasper "Meadows" Hives, who reminds him that the damages—thirty dollars’ worth of milk—must be paid and the truck returned. With Jasper by his side, Jimmy accepts a playful challenge and spends a day digging ditches in formal wear, trading good-natured jabs with the crew as they toil under the sun. The day closes with a generous gesture: Jimmy donates his winnings to a children’s charity, setting a tone of unexpected generosity amid the mischief.
When a campaign truck rolls by to hand out free cake and drum up support for the re-election bid of Mayor Olson, Jimmy’s path crosses with Trudy Olson, the mayor’s daughter, played by Joan Fontaine. The moment sparks a lively heckling match between Jimmy and the campaign worker who is really Trudy in disguise, and she dares him to do more than just talk. In a bluff worthy of his bravado, Jimmy says he’ll throw his hat into the ring, an idea that catches the public eye and unsettles the headlines. The newspapers publicize the budding political stunt, catching the mayor’s team off guard and drawing Trudy into the unfolding dilemma. She visits Jimmy at his home with a conciliatory cake, and as he pledges to clear up the misunderstanding, the two find themselves increasingly drawn to one another. She accompanies him to the newspaper office the next day to help announce his withdrawal, but she also dares him to run for real, turning a bluff into a life-changing decision.
As the campaign progresses, Jimmy and Trudy’s relationship deepens. Jimmy pursues a clean campaign, yet their interactions continue to carry a playful edge. Their chemistry grows even as a serious, shadowy plot unfolds: a corrupt police chief—who answers to the mayor—tries to frame Jimmy by luring him into a phony love nest with a hired woman and a waiting photographer, only to target Jimmy’s friend instead. In a bold counter move, Jimmy enlists the jealous boyfriend of the hired woman, a gangster, to pull the police chief into a citywide gambling ring, turning the tables on those who would manipulate the election for personal gain.
As the mayor faces mounting scrutiny over the scandal, Trudy visits Jimmy’s campaign office and overhears him negotiating with the gamblers. On election eve, during a tense debate, she confronts him with her suspicions. Jimmy responds with a dramatic show: a check designating all gambling proceeds to a children’s charity, and a recording of the police chief agreeing to participate in the illicit profits. He also reveals a recording of the mayor angrily confronting the police chief, which serves to clear the mayor’s name in the eyes of the crowd. With the corrupt parties arrested, Jimmy publicly endorses the mayor for re-election, framing the moment as a vindication for the honest candidates. In the end, the press clamor reaches a peak when they request a photo of Jimmy kissing Trudy, and she dares him to seal their partnership with a kiss, leaving the audience with a moment of charismatic resolve at the heart of the campaign.
