The root of many problems is the expectations we have that the world will work according to our likes and dislikes. When we dislike something, we find fault with the world: "It's messed up! How do I deal with it!" Could it be at all possible that the cause of the problem is not with the world, but with our unrealistic expectations?
The inconvenient yet most effective method is to use this as an opportunity to improve ourselves. Think about what this situation brings out in you, first, and only then turn your attention to others. Say, "what can I do to improve myself so that my perception becomes less negative?"
Maybe this situation is a great opportunity to try to become more easy-going about how you react to those who annoy you. Try to find at least something positive about this person. Nobody is all bad, to everyone, all the time. Perhaps this manager does something that is not obvious to you that somehow makes a positive contribution to the workplace.
Perhaps he has a way of dealing with his employers in such a way that assuages their concerns and makes them more comfortable with some of their business problems. Indirectly, having content bosses may be beneficial to the business as a whole and indirectly in some ways make your life easier in ways you are not even aware of. This may not be transparent at the moment, but try to observe his conduct a little more carefully and objectively, without preconceived notions, and try to recognize whether there is anything at all they do that could be put in the "benefit" pile.
If you find anything like that, then try to focus your attention on that aspect of their work and personality, and maybe even try to acknowledge them for it in some positive way. Sometimes a little positive attitude from a coworker does wonders. Good luck!
Finally, I would suggest to do your best not to take this person's attitudes, work style, or anything at all that they do personally, as if it's about you and all you care about is how it affects you. Try to give them the benefit of the doubt. Perhaps they are going through a tough time in personal life (which can last years, for reasons beyond their control) and it inadvertently affects their workplace conduct. Some people are reflective and self-aware enough to acknowledge this and try to divorce their work behavior from personal issues, but others are less adept at this.
Perhaps the best you could do, both for yourself and for that person, is to be professional in all your dealings with them, show understanding and give them the benefit of the doubt. This just might help nudge them toward changing some of their behaviors, at least toward you, and it will for sure make you a better colleague and professional. Good luck.
Sorry I don't have a silver bullet or some quick pill for this situation. I would advise to tread softly and focus on your work, focus on being professional with everyone at all times, try to give that person some space and not to take their attitudes and conduct personally. Work is work, at the end of the day we all go home and have a chance to leave it behind and refocus on the things that are really important in life. Good luck!
