See also, Fraternal Order of Police. A quick Google search returns many results of the low quality of fundraising by this organization, which is not rated by charitynavigator because it's actually not a 501(c)(3).
I love those license plates and fake badges in the windshield. A bonus if they have something patriotic on the vehicle too.
Nothing screams I love my country like blatantly advertising corruption and using a tax exemption to do it.
Just the other day I met someone who was able to open a gun range in a town that I thought would never let someone do it, and he showed me his gold police union card or whatever and bragged about having the state's police union as a customer for his other business via whom he was able to contact an old police boss, and of course they were able to pull the right "levers" to get the permit for the business issued.
In Washington state you can even get special license plates that say "law enforcement memorial" for an annual fee, presumably for the same purpose.
I was tempted to get these for my car+motorcycle but then I remembered I haven't gotten pulled over in 20 years so I probably don't need it.
In California I occasionally see "11-99 foundation" license plates, for $2500 any non-felon can get one and hope the California Highway Patrol will go easy on them.
My fiancee still has a rank sticker on her car from when she was dating a police sergeant before we met. It's gotten her out of so many speeding tickets (she drives like a madwoman...). When she gets a new car we'll have to peel it off and save it.
The more cops you know, the less inclined you are to get them involved in anything if you can help it. They aren't as bad as game wardens, but still best avoided if at all possible.