Same with bullhorns; even when "outside," how on earth can that EVER be allowed? Doesn't matter if it's a meeting of progressive dingbats, or Right-to-work conservatives, that's not civilized behavior. There's nothing difficult to understand about the irritation potential of very loud noise.
I think the answer to your question might have something to do with the answer to another, namely this: do the local police belong to a union?
Bingo.
Police and FF Unions are the two that still make sense, sometimes. Though they need to be limited to safety issues only.
In my area one nearby town kept putting off work on a repeater for the police radio system, causing an area to have no coverage due to
budget issues.” I.e. diverting funds to a specific demographic to gain support come election time.