Terrible Miscast
Lee J. Cobb was only 4 years older than Sinatra and they very much looked like contemporaries so it just doesn't play when Sinatra calls him "Dad."
Besides Cobb being an excellent actor, I think he may have been cast because Sinatra wanted to help him out from having been given a hard time because of his HUAC testimony. After reading Cobb's defense (of why he did it) I agree with him. Principles are good to have and some are worth dying for, but when it starts to damage your family and the people you are protecting by not testifying against people who were not too noble themselves.... The HUAC committee was vicious but the people I saw still angry against Kazan 50 years later when he got an award looked vicious to me too! Cobb and Kazan were great artists and if the artistic community can forgive or overlook that weenie Polanski raping a child, because he is "such a great artist" then they should be able to forgive or overlook Cobb and Kazan for caving in front of the lynching committee.