Ezra Taft Benson, in General Conference, teaches that Joseph Smith taught that the Constitution would "hang as it were by a thread."
Ezra Taft Benson, Conference Report (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 1963): 113
The Prophet Joseph Smith said the time would come when the Constitution would hang as it were by a thread. Modern-day prophets for the last thirty years have been warning us that we have been rapidly moving in that direction. Fortunately, the Prophet Joseph Smith saw the part the elders of Israel would play in this crisis. Will there be some of us who won't care about saving the Constitution, others who will be blinded by the craftiness of men, and some who will knowingly be working to destroy it? He that has ears to hear and eyes to see can discern by the Spirit and through the words of God's mouthpiece that our liberties are being taken. The enemy is amongst and upon us. Zion must awake and arouse herself. We, the elders of Israel can be and should be, the leaven in the loaf for freedom.