It is  fact that Plato was pretty much on the side of Sparta. That is he does not seem to be very pro-democracy as Karl Popper pointed out.. But most Greek States saw a difference between their types of constitutions and tyranny. They all considered themselves free as oppose to what they would have been under Persian rule. So what was the difference? Sparta had kings and ephors. It was the type of government they choose.The kings were limited in power. This is I think the model of government that the founding fathers of the USA.