It's funny, there's really little room for an independent Deseret in history. The Mormons never wanted their own country, just their own state. Furthermore, ever since 1833 they have preached that the Constitution of the United States was designed by God in order to provide protection to the Last Dispensation (the LDS Church). The American Revolution was a sacred event designed by God, and the Founding Fathers are widely regarded as members of the Church (baptized by proxy after death).
To get an independent Deseret, you'd need to go back all the way to 1833 or earlier for a POD, and I'm not sure how all of that would work out. The Mormons wanted to seem patriotic instead of anti-American, to garner favor with their neighbours... in order to take their patriotism out of their doctrine, the Mormons would have to be accepted by common Americans... which simply couldn't be done considering the basic foundation of the Church: the Book of Mormon and ideas of becoming Gods after death.
I've got a few ideas for an independent Deseret...
- The easiest way is to engineer a revolution from inside Mexico's empty territory while it still holds onto the Southwest. This requires two things: a higher Mormon population base and no Mexican-American War.
- A President Harrison or President Clay timeline could allow the Mormons time enough to revolt and seize Mexican territory for themselves.
- How to get a higher population base?
- Remove polygamy from the Church: more members.
- Remove all successors to Joseph Smith as prophets other than Brigham Young: less members fall away to other splinter movements.
- No Kirtland Safety Society means the Banking Crisis of 1837 doesn't bankrupt Mormons in Kirtland, which means that the membership in Kirtland doesn't rebel against Joseph Smith.
- Other ideas that could be useful in prolonging an independent Deseret:
- An independent Texas with all of its claims as a buffer state to the United States.
- Mexico wracked by an earlier, more terrible Reform War.
- Deseret includes California, Nevada, Arizona and other areas that in OTL were purchased in the Treaty of Guadalupe Hidalgo other than the territory claimed by Texas.
- An Oregon War to chastise the United States?
I'd like to finish this up by asking if anyone has ever outlined a timeline with an independent Deseret. It's such a cliche, so common, but I doubt people understand the issues behind Mormon-American relations.
Any other good ideas? Would this be an interesting timeline?