If an employer is the government, and the government is made up of its citizens, then how do we unionize?

We are, in essence, unionizing against ourselves. Franklin Delano Roosevelt made this point in 1937. Perhaps people might make the case that charter schools represent competition in the education market place, and this justifies a union. Charters schools could be considered competition, but the purpose of charter schools is to change the existing system, not to take it over. So the charter schools very existence is meant as a tool for change, and not a replacement for school districts. The moderating influence of unionization would be incompatible with a laboratory for educational innovation.