"Appoint a king upon yourselves"—Deuteronomy 17:15.
We are commanded to appoint a king, who will unite and rule over our nation. This is one of the three mitzvot the Jews were commanded upon entering the Land—the other two were building the Holy Temple and eradicating Amalek.
The king whom we appoint must command our awe. We must have the ultimate respect, reverence and estimation for the monarch—greater even than that we have for prophets. Any decree that the king issues must be obeyed—provided that it doesn't countermand a Torah law. And the Torah-sanctioned king has the right to have executed anyone who disregards his orders.