How The Constitution Will Be Saved
Channel: Following Jesus - TheLDSLife
Date: 18/10/2012

The White Horse Prophecy is a statement purported to have been made in 1843 by Joseph Smith, Jr., founder of the Latter Day Saint movement, regarding the future of the Latter Day Saints (Mormons) and the United States of America. 
The Latter Day Saints, according to the prophecy, would "go to the Rocky Mountains and ... be a great and mighty people", identified figuratively with the White Horse described in the Revelation of John. The prophecy further predicts that the United States Constitution will one day "hang like a thread" and will be saved "by the efforts of the White Horse."
Some have speculated, on the basis of the White Horse Prophecy, that Mormons expect the United States to eventually become a theocracy dominated by The Church of Jesus Christ of Latter-day Saints (LDS Church). 
The authenticity of the prophecy as a whole, which was not made public until long after Smith's death, is debated, and the leadership of the LDS Church has stated that "the so-called 'White Horse Prophecy' ... is not embraced as Church doctrine."
However, the belief that members of the LDS Church will one day need to take action to save the imperiled US Constitution has been attributed to Smith in several sources and has been discussed in an approving fashion by Brigham Young and other LDS leaders.
Several famous Mormons have made statements related to the White Horse Prophecy. For instance, former US presidential candidate Mitt Romney has said he considers the White Horse Prophecy to be a matter of "speculation and discussion by [LDS] church members" and "not official [LDS] church doctrine."