Your thinking on this is all messed up. First, God is not telling us "Clearly" as you state, to obey authority. Dig around on Chuck Baldwin's site and Lew Rockwell's and you will find that passage in Romans has been poorly taught. And remember Peter told us we "must obey God rather than men."
Also the Founders did not believe - strongly or otherwise - in the separation of church and State.
No King but Jesus, no President but Ron Paul