I think people with natural psychopathic tendencies, natural bullies, people who believe that they were born to order others around and hurt them, tend to gravitate towards "jobs" like police, IRS employees, traffic wardens or FBI agents (I guess "FBI agents are covered under "police" - ONE THING THAT STANDS OUT IS THAT ALL THESE ARE GOVERNMENT "JOBS").
Being a policeman or FBI agent is the ultimate power trip. A person in that "position" can feel superior to the rest of society, every day. It is no good telling them that they, too, have to cowtow to a MASTER. They just see this as "the natural order of things".
One way to "get under their skin" and hopefully make them think is to laugh at them or say something like (when he/she identifies him/herself as a "police officer"): "Does that make you feel special, does it?"
Unfortunately the fact that we have a lot of people who thrive on "the power trip" is evident in the "solution" to a group of kids misbehaving. You just pick out one of the kids and tell him "you are in charge, keep the others quiet and if they give you any trouble just write their names in this book". It works every time, The kid who is "in charge" actually thinks that "writing names in a book" actually means something, and most times the others will "toe the line" because they are afraid of grandma reading their name and knowing that they've been naughty.
I think the desire to control and bully others is an innate characteristic of about 10% of the population, that is a problem. We shouldn't put up with it. The only solution for the OP is to carefully vet all prospective government employees - particularly police - and weed out the 10%.