I've seen this account, Dem Saints (by which they mean Mormons) mentioned by Memetic Sisyphus
Obviously the Democrats want to infiltrate and pervert Mormonism as they did Catholicism and Protestantism, probably because Mormon states like Utah and Idaho always vote red, but I believe the Mormons won't be taken as easily.
First off, centralization. Mormonism is the richest religion in the world on paper, even more so than the VATICAN despite having a fraction of a fraction of Catholicism's billion members. Why? Because its churches aren't independent financial entities standing or falling on their own, EVERY single Mormon church or temple or anything else is directly owned by the HQ incorporated in Salt Lake City, EVERY CENT of Mormon tithing goes back to Salt Lake City and is apportioned as they see fit. If one Mormon priest goes rogue and starts preaching faggotry from the pulpit, he's out, they keep the church and all the bank accounts, probably all the parishioners too. There's no chance of a schism where the offshoot takes buildings and money. None. Maybe this is a lesson Mormons learned from their many schism in their early days. Because churches can easily be taken away from woke clergy and schism isn't really an option, Democrats can't use "What about a schism!" as a cudgel to make Mormonism change itself to appease them. It's take it or leave it.
As for the so called "Prophet" the succession is based on seniority in the leadership. There is no cardinal election to infiltrate with lefty clergy, there is no question of "is the next prophet the woke or traditionalist candidate?" the next prophet is set in stone before the current one's death, as is the one after that and the one after that 10 layers deep. The youngest in line are in their sixties and will be in their eighties and nineties before they reach the front of the line, nothing short of mass assassinations can change that.
But what of waiting for every living member of the governing body to die and then replacing them with woke ones over the next 50 years? The positions tend to be unofficially hereditary, passed down in the same families from the pioneer days for centuries. Newcomers are exceedingly rare. So Democrats wouldn't just have to wait out the lifespans of every living member of Mormon leadership today, but for the extinction of their entire extended bloodlines as well. And Mormons have the highest reproductivity rate in the country, making that extremely unlikely.
It just isn't a religion that lends itself to lefty infiltration tactics. They'd have a better chance infiltrating ISIS or Al-Qaeda to turn them woke!