Charismatic roving peddler Hank Martin falls in love with schoolteacher Verity Wade and soon marries her. On their wedding day, he rents a ramshackle home from his upper class lawyer friend Jules Bolduc. Hank gathers some of his many friends to fix the place, but Verity begins to realize that he is not as nice as he appears to be; while they do the work, he sees nothing wrong in going inside to read a law book. He confides to her that it is all a matter of manipulating people the right way.

Jules invites the couple to dine with him that night, but Hank soon quarrels with another guest, Robert L. Castleberry IV. He accuses Castleberry, the owner of a company that buys cotton, of shortchanging the poor farmers.

When Hank goes about his business, Verity accompanies him to the bayou. A young woman named Flamingo leaps into his arms, but when she learns that he is married, she tries to arrange for an alligator to rid her of her rival. Verity is only injured. However, Flamingo does not give up on the man she has loved since she was a teen. After Hank sends Verity home to recover, Flamingo tracks Hank on the road. She overcomes his resistance, and they start an affair.

Hank sets out to prove that Castleberry is cheating. When Hank proves that the weights used are seriously inaccurate, one of Castleberry's men aims a rifle at one of Hank's followers, and he is killed by farmer Jeb Brown.

To avoid inflammatory publicity, Castleberry sees to it that Brown's murder trial is repeatedly postponed. Shadowy power broker Guy Polli offers to use his influence to get the case heard in return for Hank's "thanks". When Castleberry manager Samuel T. Beach shoots and mortally wounds the prisoner, Hank persuades the dying man to go to court anyway. Although Brown dies, Hank has time to persuade the jury to declare him innocent posthumously before the judge can adjourn and to tell the true story to the gathered press.

The resulting publicity forces Castleberry to sell his company to Polli (it turns out that his managers were the ones behind the fraud), and enables Hank to run for governor. However, a major rainstorm the day before the election prevents many of Hank's rural supporters from voting. In desperation, he goes to see Polli. Polli offers the votes of certain city precincts he controls, but in return, he insists that Hank sign an affidavit stating that Beach was with him at the time Brown was shot; the company Polli has bought would be destroyed if Beach were convicted. Hank reluctantly agrees.

Each candidate wins the same number of counties, but the state assembly that will break the tie is controlled by the incumbent. Rather than try again in four years, Hank urges his supporters to march on the capital as an armed mob. Just as they are starting out, Jules arrives, stating he has proof that Beach is Brown's murderer and that Hank knowingly signed the false affidavit to get Polli's support. When Verity confirms Hank was with her at the time of the killing, Brown's widow shoots Hank. As Hank is dying, he tells his wife that his supporters were smarter than he thought.

The Washington Evening Star was not impressed: “A Lion in the Streets is a dramatically shallower work than All the King’s Men, for which it is too precise a parallel. For all of Cagney’s ranting imitation of a political psychopath, his screen play has none of the bite, sting or shape of the earlier film.”^[1]

The Brooklyn Eagle was also lukewarm: “Though James Cagney is the star, and attempts to give one of his two-fisted performances, there are so many unexplained gaps in the story that at time he appears to be merely shadow boxing. Only portions of the book have been used, and the sometimes touched upon so sketchily that the film gives the effect of a trailer, jumping from one incident to another out of turn. Many of the Paramount [theater] patrons seemed to be under the impression that they were viewing a comedy at an early showing yesterday, laughing out loud at Cagney’s speech-making and his intermittent Southern accent and even finding funny the most serious moments of the film. Their attitude was understandable because, with its picturesque backwoods characters and disconnected methods of telling the story, the production often takes on a musical comedy air.”^[2]

Variety was also unimpressed, despite finding strength in some of the acting. But too much of James Cagney's stylization made a wrong impression, and the film as a whole was "just an average drama."^[3]

Bosley Crowther of The New York Times gave a favourable review, calling the movie "headlong and dynamic." His only reservation was with the color photography, "which doesn't do the gaunt gray subject any good."^[4]

A Lion Is in the Streets was presented on Grand Central Station March 16, 1946. Jeanne Cagney starred in the adaptation.^[5]

• A Lion Is in the Streets at IMDb  
• A Lion Is in the Streets at the TCM Movie Database
• A Lion Is in the Streets at AllMovie
• A Lion Is in the Streets at the American Film Institute Catalog