It is true that Edgar Bergan and Charlie McCarthy were far more effective in their national audience on radio than in the movies. This was due to the close-up affect of cinematography on Bergen's face - he could not hide the fact that his lips moved a little. When on a stage in a nightclub or in vaudeville he'd be too far away to be seen moving his lips. Not so on film.
But Bergan and McCarthy put ventriloquism on the map. Their act and radio show took the art of throwing one's voice and brought a biting humor to it, giving the dummy a real personality: a wise guy little man, with an eye for the ladies and an eye for making trouble for people he did not like (among whom was Fields). The feud of McCarthy and Fields mirrored the contemporary feud of Fred Allan and Jack Benny, except that Allan and Benny were both real. But on radio Charlie was as real as "Uncle Claude" was, so the fact that it was a block of wood that was manipulated fighting a real life man did not matter. The public just loved Charlie reminding Fields of his alcoholism, in particular his large red nose. And the public loved the threats of Fields to give Charlie a ride on a buzz saw.
Because of the strong personality of McCarthy, a movie audience even today looks at this film and tends to ignore Bergen's slight lip movements. Charlie is the real personality of interest, not Edgar - here playing a hard working young man who would like to marry Vicki Whipsnade (Constance Moore) but is resigned that she wants to marry a wealthy young wastrel instead. Bergen could act (look at his performance in I REMEMBER MAMA, as Ellen Corby's boyfriend/husband, and his comic scene there with Oskar Homolka regarding the dowry). But he did not have to act as Bergen here - all he had to do was let Charlie do his job (and, for that matter, let Mortimer Snerd do his work too in two scenes). The tricks used by the director to have scenes where Charlie appears without Bergan are just even more effective, as they enhance the idea of an independent comic personality coming out of the dummy.
For Fields there are many choice moments too. His walk, supposedly naked after a shower, across the circus grounds - hidden behind people carrying items, or elephants and other animals, until a lady screams and faints (and Fields is finally physically revealed to the audience) is a gem. So is his wrecking the Bel-Goodies engagement party, first by his mad ping pong match, and then by his insistence of telling the story of how his life was saved once by an intelligent rattlesnake (not realizing that Mrs. Bel-Goody hates even the mention of snakes). His interactions with the circus staff, with the idiotic Grady Sutton, with labor union organizer Edward Brophy, and with the various people buying tickets for the circus, or for that matter mispronouncing his name as "Larceny Whipsnake" are priceless. So is his own attempt at ventriloquism: he does it so you can't see his lips move, but you just can't believe he is throwing his voice. Well he is throwing dust or something else at that moment.
But it is his running confrontations with McCarthy, some of which he actually loses (he has one where he has to bribe Charlie at one point to keep quiet) that maintains the audience's attention. The film is one of Fields' best ones, and deservedly retains it's popularity to this day.
