It is my contention that the notion of "theocracy" is badly misunderstood. Many equate a theocracy with civil rulership by the clergy, such as occurred prior to the English Protectorate. I would argue that this should be more correctly called an "ecclesiocracy."
A theocracy is the rulership of God (theos = God / cracy = rule). God rules through His Son, Jesus Christ, by His Word, the Bible. His rulership applies in every area of life and, as such, the Bible commands how to conduct affairs as God ordained.
When politicians listen to the instructions of the Bible, and make good laws in the light of what the Bible teaches, the politicians function under the rulership of God; this is a theorcracy.
It is the role of the clergy to simply and clearly spell out what the Bible says. It is not the role of the clergy to assume seats of civil government. Ecclesiocracy is not Biblical; theocracy is.