I do struggle somewhat with unions for public servant though. The reason being is that it's easier for them to be granted their wishes because their pensions and stuff are backed by the full faith and credit of the US or State government.
That would be a good point, except for the fact that the government can simply pass a law to force employees back to work with humongous penalties for anyone who would dare to defy it, would the union fancy using a strike as a negotiation measure. Where I live (Canada), the government even passed laws to that effect on private companies that used to be public (one railway company whose name eludes me right now and Air Canada. I can find references if you're curious).