It was a prophecy given by one of the early LDS churches leaders. IIRC it was Brigham Young.

Many members of this church just need to wake up to the awful state of their situations in regards to the self claimed secret combinations (all members of the Church of Jesus Christ of Later Day Saints know this is the biggest problem. In governments & will be reminded of it this year again) in the federal government.

Sure there are corrupt members of that church. Romney really seems like one to me. Though the vast majority are great individuals who simply want to help lift their fellow man & are willing to give hundreds of volunteer hours individually to help others in need every single year.

edit - seems I recalled this correctly. Here is more info on the claim

Heber C. Kimball: “After a while the Gentiles will gather by the thousands to this place, and Salt Lake City will be classed among the wicked cities of the world.” This is from a talk in 1868 by Heber C. Kimball (apparently published by the Deseret News 23 May 1931)