Robert Mitchum did not receive an Oscar nomination for portraying Paddy Carmody in The Sundowners.
One thing notable about this film is that it is set in Australia, and to go along with that many of the cast members put on Australian accents to varying degrees of success. I will say none of the accents are ever distracting Mitchum included even though it really does hide his distinct voice. Although it might seem a little different at first the accents are actually well handled and it does help create the setting, and the accent never overcomes the characterizations.
Mitchum as the patriarch actually has less thankful roles. It is Deborah Kerr as Paddy's wife Ira who gets the more emotional moments that really drive the film. Peter Ustinov as a bit out of place British former captain but current herder and Glynis Johns as a hotel manager get to be the scene stealers. Mitchum actually stands as the man in the middle who stays pretty consistent in the film, what happens around him rarely changes how Paddy ever acts.
If there is an actor to portray a steadfast man who is going to do his thing his way no matter what it really is Robert Mitchum. Mitchum as usual has his strong presence in the role that is always effective in portraying the confidant nature of his character. He really is not nearly as strong willed though as Mitchum can be, but he effectively does tone it down to an appropriate degree to be able to portray Paddy's less noble qualities.
Paddy has a few problems one being he is not opposed to drinking money away, nor is he opposed to gambling it away either. Neither Mitchum or the film really give these that much weight, although they don't really have to as the film simply is not about Paddy being a drinker or a gambler. Mitchum deals with these fairly lightly as to fit the tone, and actually does work them in just fine by believably showing that they are simply just Paddy's normal habit nothing more.
The best part of Mitchum's work here probably is the very important chemistry he has with Deborah Kerr. It is very understated between them by well handled by both. Their relationship is very much non verbal at times and effectively so. Even though they certainly do not constantly say it, as the two have few overtly romantic scenes, but their love still is made genuine in both of them even though for the most part it is unsaid.
The main conflict in the film comes from the fact that Paddy wants to keep moving even if his family wants to starts settling down. Mitchum portrays this more as just something Paddy feels he needs to do more that some ache or drive. Again I feel perhaps maybe there should be something more overwhelming about his want, but then again Mitchum shows it as something enough to be believable as well as the way he portrays does fit in with the tone of the film.
This is entirely just a fine performance actually from Robert Mitchum and he actually does everything well. Technically speaking it would seem aspects of the character could have perhaps been weightier but than there would be an extremely different film and not necessarily a better one. It is hardly his best performance, and certainly is not the best thing about this film but he manages to do what he needs to for his role.