The History of the State in the Early Christian Tradition

I think it's astonishing how long it took for the Christian tradition to really begin seriously looking at the state with a skeptical eye. For example, if I look at the early centuries of Christianity, when Christians are sporadically being persecuted by the Roman Empire, there is no tradition of thought developing that questions the legitimacy of this. Now you do later in the second millennium AD, you do get some theorizing about the possibility of deposing an unjust ruler. But even that is not really a full-throated attack or let's say analysis of what the state is capable of.