Been awhile since I've been in SLC and can't really break down the population by Religious Affiliation within the City, but there are some noteworthy Demographic considerations to consider....
1.)
There is a significant Latino Population of 42-45% in the North-Central neighborhoods of Rose Park and Fairpark, and about 36% in the NW neighborhood of Westpointe.
Although the Latino population skews younger, it still accounts for for a significant chunk of the population aged 18-44....
There are also significant African-American and Asian-American population in these same neighborhoods.....2.) Although the Central and Northeastern Parts of North SLC are much more heavily Anglo, they also include some constituencies that for different reasons have tended to skew a bit more Democratic in recent years....
A.)
University Populations---- This part of SLC is home to the University of Utah, where the Campus precincts combined with the off-campus precincts with an overwhelmingly Undergrad Aged population went +52% D in the 2016 Presidential election (66% D- 14% R- 21% Others).
Here's a link to some research that I did on a thread I created on the voting patterns of Undergrad populations within Division I-A football Universities:https://uselectionatlas.org/FORUM/index.php?topic=273504.msg5926059#msg5926059Now, the important thing to note here, is that I used a very "conservative criteria" for inclusion of Undergrad student precincts, so these numbers aren't really representative of the of the overall "reach" of the campus population in these neighborhoods, which would likely include not only additional undergrads, but grad students, professors, and faculty as well.
B.)
Government Sector Employees----This part of SLC is home to the State Capitol, and although I'm sure that State Employees live in various locations throughout the City and County, it wouldn't surprise me if those workers that have chosen to live in a more centrally located part of the City, tend to skew a bit more Democratic than those who reside elsewhere.
C.)
Younger Populations--- This generally a pretty youthful part of the City, with extremely high concentrations of younger populations located in the Downtown and Central City neighborhoods, and relatively small populations of Middle-Aged and Older voters....
This is obviously an age demographic, even in Utah that will tend to skew quite a bit more Democratic.
D.)
Upper-Middle Class Voters----
Although in general most of the neighborhoods in North SLC aren't particularly impressive in terms of Median Household Income (MHI) compared to a few neighborhoods in the SE part of the City, you do have some neighborhoods such as Greater Avenues, and the Northern part of Eastbench that are pretty well off compared to much of the City.
To summarize, even without doing a comprehensive precinct level analysis overlapping with social-demographics for the '12 and '16 Presidential elections, let alone trying to map the LDS / Mormon vote by region within SLC, it does appear that we might have at least something to work with when trying to explain the Northern SLC Democratic voting habits.....
