I don't like Frank Capra
I only watched 25 mn :
You easily spot that Frank Capra is the father of all modern cinema, and this movie inspired every one, for example Sidney Lumet (12 men...) all modern cinema which deals with men at work and social matter rather than romance and melodrama, but also French and Britain movie makers where influenced, the "nouvelle vague", alain résnais, joseph losey, because of the surrealist/ weird content.
So this is one of the most important movies ever. It's unbelievable modern ! no music, to make it more realistic. It is both realist and beyond realism regarding the lot of animals for example, every one has an animal. The dancing scene is also too nice for being just real.
I don't like James Steward here, and his mannerism (hands...)
Why the link to Sydney Lumet ? Well, notice that people are introduced without names, so who is the leading character ? the focus is on a series of types, rather than individuals. It's a portrait of main types in the society, average American individuals. Every characters stands for a lot and is somewhat too clear for being a real individual. That's the problem, if you paint all society, you can't seize an individual. Anyway in my opinion, we can't really look inside the characters and have empathy with them, because we don't know them very much...
This was certainly the path toward modern cinema, trying to make something new, getting rid of old scripts and overcharged emotional content. You can also see Orson Welles here (well i don't like him neither).