Mitt Romney as president?

Since the Mormon Church believes it has a living prophet "who is not limited by men's reasoning" and can receive revelation from God on any subject and involve himself in civic matters, I believe a fair question, to be asked respectfully of Governor Romney is "Given that the president of your church is considered a "prophet , seer, and revelator" and the living mouthpiece of God on earth, if you faced an important decision as president of the United States and received a personal phone call from the prophet saying that God was instructing to you take a certain course of action, would you be obligated to obey? Why or why not?" Is this not a fair question?