Richard Jenkins ... always an excellent choice if he's available. Such a range this guy has - and his performance here is matched by his .. well "successor". While he is on his way out, he will get replaced and has to teach the guy who comes after him how to do the job he did.
The fact that the guy is an ex con and way younger than our leading man ... well it has to lead to some conflicts. For better or worse those two have different world views. And whether you agree with one or the other ... it does fuel the story and the character development ... and adds tremendous drama to the whole thing. Some other great additions in the acting department round up a really interesting drama - slow moving, but good, with many themes that will connect to a certain target audience.