Late last night, I saw this on Twitter:

My response was:

I had a couple of things in mind here.  First, the police are supposed to operate within communities where the rule of law is established, and to preserve that rule of law.  Unionization makes them likelier to do this.  In some places in the world there are still radical trades unions, but in most places most unions are pretty thoroughly interwoven into civil society.  Pay your union dues, go to union local meetings, etc, and you’ll be constantly reminded that you are part of the local community and that you have a stake in the well-being of your neighbors.  Each time you receive one of those reminders you become that much more likely to act like a human being while you’re on the job.  Combat forces, by contrast, have as their mission “to engage the enemy and to destroy him,” as the US Army Infantry Field Manual used to put it.  If we forbid unions in the military, that is largely because we want our warriors to remain aloof from the people we are sending them to kill.

That’s a sort of generalized communitarian point.  Second is a more left-wing kind of point.  Collective bargaining between representatives of the average cop on the beat and the representatives of the city governments shows that average cop that s/he makes a living by working for wages and as such has more in common with other wage-earners or would-be wage earners than with the people who call the shots in politics, which is to say the people who live primarily on the proceeds of capital.  That isn’t to say that unionized police will want to abolish capitalism; careers in police work tend to be more attractive to very conservative people, and for that matter I’m inclined to support capitalism myself.  But I do believe that the only legitimate power is limited power.  And a police force staffed by officers who know that their economic interests are further from those of the average politician or politician’s paymaster than they are from those of the average suspect is a definite limitation on the power of economic elites who are always eager to use the law as a weapon to intimidate those who get in their way.

Here’s a clip from the 1976 documentary Harlan County USA, in which a unionized coal miner, in New York City to protest outside the headquarters of the company against which he’s been on strike for nine months, talks with a unionized NYPD patrolman.  The seventies are ancient history in a lot of ways, of course, but this is still a good illustration of the general points I’m making here: