"Behold, I have given him for a witness to the people, a leader and commander to the people" (Isaiah 55:4).
The text above refers in particular to David and especially to that greater Son of David who would eventually become the eternal heir of "the throne of His father David" (Luke 1:32). Jesus Christ is indeed "the faithful and true witness" (Revelation 3:14), the leader who will care for even the least of His followers, and the great Commander of the whole wide world, the one who "commandeth even the winds and water, and they obey Him" (Luke 8:25).
Now while our text refers directly to David and ultimately to the Lord Jesus, the words themselves could also well be applied to each of the great men who have been chosen by God to be the leader and commander of our great nation, as well as its most effective witness from his "bully pulpit" to other nations. We must remember, even though our various presidents have been elected democratically to serve in that office by the people of the nation, that nevertheless, "the powers that be are ordained of God" (Romans 13:1), and they are therefore "God's ministers" (Romans 13:6).
Some may seem unfit for such a role, but we must reckon with the truth that "the most High ruleth in the kingdom of men, and giveth it to whomsoever He will" (Daniel 4:17).
God can judge and deal with all such leaders in His own time and way. As citizens and subjects, it is our responsibility to "Fear God" and "Honor the king" (I Peter 2:17), or whatever title our leader may have. Whether or not we voted for the president, therefore, we must honor him, pray for him, and follow his leading, except only when God's commands negate his. Then we must obey God (Acts 5:29), and accept the consequence. HMM