It is about a man, Tom Garner, who works himself up from humble beginnings to become a powerful and wealthy man (he is in the railway business) but who alienate his family and dies alone. At the moment of his death he utters one single word. The film begins with the death and is then told in non-chronological flashbacks that take place on three planes, the rise from childhood, the fall, and the present day, and is quite intricate. So the connections with Citizen Kane are rather obvious. Welles though said (in This is Orson Welles) that he had not seen The Power and the Glory and since he was in general not shy of highlighting his inspirations he was probably telling the truth. But it is of course possible that Herman J. Mankiewicz, the co-writer on Citizen Kane, had seen it.
The script was so advanced that a new word was coined in order to explain it, "narratage", a term that did not really catch on. It refers to the use of a complex flashback structure that is authored by a voice-over to help give a sense of order and continuity. The Power and the Glory was not the first film with a flashback structure, that was common enough, but it was pushing the concept further.
The person who tells the story is Tom's friend Henry, one of the few who actually liked Tom. But how does Henry know all these things? In one scene Tom asks Henry "Do you know?" Henry answers "No." and Tom replies "It's a secret." Yet Henry has told us about it, or rather, he is in fact telling us about it, so he does seem to know. Is he even to be trusted? There are many in the film who are deceitful after all. The most remarkable deception is when Tom's second wife becomes pregnant and it turns out that it is not Tom but Tom's son from his first marriage who is the father.
The cinematographer of The Power and the Glory is James Wong Howe and there are some striking deep focus shots (such as when Sally Garner decides to kill herself), and there is a fine visual connection between the beginning and the end, with lights beaming through the windows in the opening sequence (the funeral) and the scene at the end when Tom dies. Howe and the director William K. Howard did several films together and who was primarily responsible for the look of them is hard to say.
The director William K. Howard was listed under "Subjects for Further Research" in Andrew Sarris's American Cinema and he has not yet been properly research. But he has made a number of fine films, sometimes working with James Wong Howe, and he had style and force. An important early film is said to be White Gold (1927). Another is Transatlantic (1931) and then there is the inspired The Princess Comes Across (1936), where Carole Lombard plays an actress who pretends she is Olga of Sweden, whom she plays as if she was Greta Garbo. If ever there was a meta-performance...
The theme of The Power and the Glory is similar to Citizen Kane, and many other stories as well. It is perhaps one of the oldest of tales, how greed and ambition can ruin a person. On his deathbed Tom utters one word. The word is "Sally", his first wife and one true love. He lost her, and everything else that mattered.
Here is an earlier post about Sturges. When Sturges directed his first film, The Great McGinty (1940), which he had also written, he was again telling the story of the rise and fall of a man through flashbacks. It is less complex and more light at heart, but a very good film.