Imagine every member of a population were appropriately represented in government. And they all agreed that a select group of people could punish them, whenever certain rules were broken. Would you consider that coercive?

Have they voluntarily entered an explicit contract with the rulers (while not under duress by those same rulers)? No citizen in the world right now has. If not, it's coercion - and more importantly a rights violation by the 'rulers' against the 'ruled'.