Memes

Police unions do not see themselves as part of this movement. With one exception – the International Union of Police Associations, which represents just 2.7% of American police – law enforcement unions are not affiliated with the AFL-CIO, the U.S. labor body that unites all unions.

Because as outlined culturally the police see themselves as the system itself, by nature of the job, as evidenced by their hostility towards the larger labor movement they're often tasked with breaking, something the vast majority of other union heavy vocations don't do, and are often given special carve outs when the labor movement and unionization are targeted legislatively precisely because it's their job to enforce those rules.

American police are more a capital defense force, and unlike the larger labor movement, have their priorities of being unaccountable to those they police backed by the state. They're the owner's special little boys/girls, they attract and recruit conservative minded power seekers who conflate legality with morality, and they like it that way. Note their awesome insurance, their massive starting salaries with high school education, they have little to complain about. Not to the owner's level at all, but they don't live in the same America most do.

They probably could take this country for themselves, but have you ever met a cop who wasn't a fan of structure for its own sake?

Imma just take a stab in the dark and say conservative/classical liberal ideology keeps them licking the toe jam of the owning class.

They love them some hierarchy.