According to Joseph Fielding Smith Joseph Smith did teach Constitution would hang by a thread.

Date
Apr 9, 1950
Type
Speech / Court Transcript
Source
Joseph Fielding Smith
LDS
Hearsay
Scribed Verbatim
2nd Hand
Reference

Joseph Fielding Smith, Conference Report (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 1950): 159

Scribe/Publisher
Conference Report
People
Joseph Smith, Jr., Orson Hyde, Joseph Fielding Smith
Audience
Latter-day Saints
Transcription

I must not take more time but to add this: The statement has been made that the Prophet said the time would come when this Constitution would hang as by a thread, and this is true. There has been some confusion, however, as to just what he said following this. I think that Elder Orson Hyde has given us a correct interpretation wherein he says that the Prophet said the Constitution would be in danger. Said Orson Hyde: I believe he said something like this--that the time would come when the Constitution and the country would be in danger of an overthrow: and said he: ""If the Constitution is saved at all, it will be by the Elders of this Church."" I believe this is about the language as nearly as I can recollect it. (Journal of Discourses 6:152.) Not I tell you it is time the people of the United States were waking up with the understanding that if they don't save the Constitution from the dangers that threaten it, we will have a change of government.

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