We are called to be priests and kings.
He washed us from our sins in His own blood, and has made us kings and priests to His God and Father (Rev 1:5-6).
Since the reformation, Christians have been serious about the priesthood of all believers, even though we do not always practice it.
We have not taken the kingship of all believers nearly so seriously. We are kings.
A king does not need another king to rule him. If he surrendered to another king, he would stop being a king.
If Christians are kings, they don’t need a king or some other political system to rule them. We need to work out what that means.