Melvyn Douglas is the father Tom Gene Hackman is the son Gene. Gene Hackman who was nominated in the supporting category is the true lead in the film not Douglas. Douglas I would say boarders on both categories because he does have a few scenes were he dominates the film, but at the same he disappears from the film for some relatively long stretches.
Douglas first appears being not exactly the most original type of character, which is the stern and sometimes casually cruel father. Douglas is effective in handling this, and does try to make his own mark on this sort of character. Although it is not an entirely original character at this point, Douglas does a good job in showing clearly that this is just standard for Tom in his precise and commanding fashion toward Gene.
Melvyn Douglas is allowed to do more when his wife takes a turn for the worst. Douglas is given two scenes where he shows how much he honestly cared for his wife, which are both quite astounding. Douglas shows the saddening loss in his character quite brilliantly. I think a particularly strong moment in this is when he is looking at the different coffins for his wife's funeral. It is an interesting scene as he tries to sort out the coffins as well as his feelings around the change in his life.
Douglas after these scenes though he certianly disappears for a bit, and comes back when his daughter and his son attempt to deal with him. Douglas is again quite strong in his fight with his daughter, as he constantly defends himself by saying he has had a hard life, and according him his children were not making it in his mind that they owe him. Douglas is again good in showing that this simply his defense mechanism he always uses against his children, but also below it he does suggest a deeper sadness of his character, and a fear of being alone, as well as losing his mental capacity.
The most important moment of Douglas' whole performance is Tom's final talk with Gene at the very end of the film. It begins with them discussing both their own relationship as father and son, but also Tom's own relationship with his father. It is a fascinating scene between Hackman and Douglas because together they create what is an actual connection between father and son, and Douglas shows incredibly well the sad of history of his character, as well as the honest love he does have for his son as well.
After this though their conversation does a 180 when Gene announces he is leaving, but tries to convince Tom to come with him. It is amazing how they change from honest love, to hostility so quickly, but both actors make the change entirely convincing. Douglas is incredibly strong in presenting that Tom simply cannot give in to changing what he sees as right no matter, what even if it means completely losing his relationship with his son. Douglas' flawless change from emotional honesty and love, to emotional brutality, and defensiveness in Tom makes the final scene truly great, and truly heartbreaking. Overall Douglas' whole performance is a strong effective performance, that works exceedingly well with Gene Hackman's true lead performance.
