I must respond to Bob Pr.'s comments below - I can't let such a slander against Frank Capra go unchallenged. :)
******** Quoting Bob's Review: Frank Capra was the director and I understand from our discussion that Capra's autobiography thoroughly "dissed" Harry, apparently in revenge for Harry having fired the young Capra from directing any more of his films. The two originally had been close until that point but had frosty relations after. Our discussion leader said many people are now beginning to re-evaluate Capra's revengeful pique, the significance of Langdon's contribution, and appreciate him much more. *********
Wow, I really didn't get that sense from Capra's autobiography at all. Capra praised Langdon's talent very highly, saying he was as brilliant as Chaplin etc. The thing is, according to Capra, Langdon didn't really understand what made him (Langdon) so special and wanted to BE more LIKE Chaplin, instead of being himself and being equally great in his OWN way. Apparently Langdon didn't "get" the character that Capra helped to create, the persona that was so beloved by the public. Like many people, he wanted to be something he was not.
Capra claims that Langdon let stardom go to his head once the films they made together became big hits. That Harry started taking all the credit, not acknowledging (and actively insulting) Capra and the others who had helped him along the way. That's not so very hard to believe - success/fame (especially if it comes all at once) tends to affect most people this way and swell their heads. Capra tried to warn him about the swelled head and bring him back down to earth, and was fired. Too bad Harry lacked humility and succumbed to typical Hollywood Diva behavior (my words, NOT Capra's.)
If you want to cast Frank Capra as the Villain here, because you find it hard to believe that someone as guileless and innocent on-screen, as Langdon appeared to be, could be an ambitious and egotistical jerk in real life (again, MY interpretation, not quoting Capra here!)...well, that only proves Harry's abilities as an ACTOR, eh?
I recommend reading Frank Capra's book for yourself, instead of relying on second-hand information. I'm sure you'll see the genuine sorrow he felt after Langdon proved he *couldn't* do it all on his own, the quality of his films dropping fast when Capra was no longer involved. If you doubt how important Capra was in their partnership, ask yourself: after they stopped working together, which of the two continued to achieve greater and greater success, and whose film quality & career went to the dogs? Langdon obviously needed Capra more than Capra needed Langdon.
I really believe Frank Capra was heartbroken over the way things turned out, and about Langdon's wasted potential. It didn't seem to me he took any vengeful pleasure in seeing Harry fail and fall into obscurity. There's one particular anecdote Capra remembers - passing by the set of one of Langdon's later films, where the director was treating him like crap and clearly didn't understand Harry's strengths as a performer, trying to make him do things that just didn't come naturally to him (ironic since Harry had previously wanted to be like other comics). I wouldn't have blamed Capra if he HAD gloated a bit in his autobiography, but instead he sounded upset about this incident.
Personally I don't have as much sympathy for Harry as Frank seemed to - Harry treated "the little people" (behind the scenes writers & directors) like dirt, and made the decision to turn his back on those people he should've been grateful to. Pride comes before a fall, and all that jazz.