A dark horse is a person or thing that is an unknown element. In the old West town where Jingles and Wild Bill find themselves an election is in progress. Two spinster sisters are the only ones around who are brave enough to not fall for the politics of the front running candidate. His only competition has been eliminated, and sent out of town. Rather than letting the corrupt man win, the sisters nominate their own candidate at the last minute. Jingles.
Tensions run high as the polls approach closing, and Wild Bill has some troubles of his own on his hands to resolve. Will Jingles win? Will he serve as mayor if he gets elected? Be sure to listen in to see how things work out.
PS: In a recently posted show of Jack Benny, a 1938 episode, Jack is teased about being elected as dog catcher. On that show he also jokes that Andy Devine was mayor of Van Nuys, which he really was at the time. Whether he still is at this time, 12 or so years later, is doubtful but he at least had the experience of really being mayor in real life.