Just wow. Do they really believe this?
Yes the original white horse prophecy came from their Mormon false prophet Joseph Smith and was mentioned many times for decades later as being belied and true since “the prophet Joseph” said it...
“[T]here will be a complete change of government. Washington, D.C. will cease to be capital. The present national bureaucracy will have its end. The internal conflict will sweep away the current system of governments and will pave the way for the political kingdom of God and the millennial kingdom through which Jesus Christ will rule and reign.... A new government will be established among the saints and that political Kingdom of God will espouse and uphold the principles of Constitutional government.”
“You will see the constitution of the United States almost destroyed. It will hang like a thread.... A terrible revolution will take place in the land of America.... [T]he land will be left without a Supreme Government,... [Mormonism] will have gathered strength, sending out Elders to gather the honest in heart... to stand by the Constitution of the United States.... In these days... God will set up a Kingdom, never to be thrown down.... [T]he whole of America will be made the Zion of God.”
- Prophet Joseph Smith, Jr., May 6, 1843, in Roberts, Journal of John J. Roberts, online at http://www.helpingmormons.org/white_horse.htm