As I've mentioned previously, I'm now in the third year of a multi-disciplinary Ph.D. on church and state. We select our own reading list under supervision from four different professors and prepare for comprehensive exams prior to beginning the dissertation.
I'm currently reading Lectures on Calvinism, a reprint of Abraham Kuyper's Stone Lectures at Princeton. Having put away half of the book, I'm wondering how I could have possibly come this far in the study of religion and government and not read this man previously. He's always been out there, a ghostly image of a Christian statesman, newspaperman, pastor, and professor who was once prime minister of the Netherlands, but I had never engaged his writing. It is profound and enlightening.
One of the most interesting ideas I've come across from him is that of "sphere sovereignty," where the state is only supreme in its particular sphere. It is the rod that holds up a weak plant. It is in service to God as a restraining hand upon the evil sin may do. It may not disrupt the sovereignty of other spheres like the arts, the family, the university, the church, business, and the sciences. The key insight is that the state is not omni-competent and it is not the first institution of a society. Others are more organic and occur prior to it. This more limited idea of a state, Kuyper argues, is what lies behind the American constitutional impulse. He certainly seems correct in saying so.
Maybe more later, but in the meantime I urge any interested readers to get hold of Kuyper's Stone lectures in whatever form and pay particular attention to the section on Calvinism and Politics.