I would say that Mormonism would make it even less likely. In my experience (I was raised Mormon), they tend to be even more ideological than southern protestants. That being said, the TRAX does connect with Temple Square, which I'm sure provides some utility to Mormons even if they only use it to avoid parking problems for General Conference (2x per year).
Honestly, I think the defining attribute about SLC was that they did what they set out to do, they did it within budget, and they exceeded ridership expectations. It basically silenced all the ideological opposition and let the projects be judged on their merits.
There's a huge racial aspect in anti-mass-transit politics in many American cities that's missing in SLC. Transit is fundamentally urban, and in a lot of the country 'urban' is code for black.
SLC is heavily Democratic, like a little San Francisco, while the outer suburbs are the most Republican urban areas in the USA. Utah County's suburban voters make it the most Republican urbanized place in the USA with frequent 80+% results for Republican candidates.
But both areas -- Salt Lake and Utah counties -- vote for transit.
Part of the reason is that there is no Religious Right in the Utah Republican Party. The local Republicans are libertarians, western Republicans, country club Republicans, and big business Republicans. But that cultural revanchiste Religious Right just doesn't have a foothold in Utah. The organizations that promote it are unrelentingly hostile to the Church (Specifically the Church of Jesus Christ of Latter Day Saints).
My theory is that the people who hate transit are linked to the Religious Right cultural suburbanists and possibly the Neocons. Utahns may happen to live in suburbs, but aren't emotionally invested in hating the kind of people who ride the train. Also, Utah suburbs tend to be close knit because of the prevalence of one church where the community meets regularly.
Honestly, I think the defining attribute about SLC was that they did what they set out to do, they did it within budget, and they exceeded ridership expectations. It basically silenced all the ideological opposition and let the projects be judged on their merits.