The evidence is reasonably clear that places with more mainline Christians supported Trump more than they supported Romney, while places with more Roman Catholics supported Romney more than they supported Trump.
The trends were not monolithic, however.
Denominations whose members favored Trump more than Romney:
1. ELCA Lutherans (1.85)
2. Missouri Synod Lutherans (1.26)
3. Disciples of Christ (1.14)
4. Nazarene (0.81)
5. American Baptists (i.e. Northern Baptists) (0.76)
6. United Methodist Church (0.64)
7. Southern Baptists (0.28)
Denominations whose members favored Romney more than Trump:
1. Mormons (-10.61)
2. Presbyterian Church in American (Southern Presbyterians) (-2.01)
3. Non-Denominational Christians (-1.49)
4. Roman Catholics (-0.98)
5. Assemblies of God (-0.56)
6. Presbyterian Church USA (Northern Presbyterians) (-0.50).
The Mormon case is fairly clear. Romney was a Mormon and Mormon leaders mobilized around Trump's immorality, in part, by offering a third-party candidate who was a Mormon establishment Republican.
Roman Catholics had the comfort of knowing that Romney had been a Governor of a state with a large Roman Catholic population who was a moderate who created the model for Obamacare, while the Pope himself offered cues that Trump was a man to avoid.
What is going on with Lutherans? More plausibly, Lutherans are heavily concentrated in the Rust Belt and in rural areas, as are Disciples of Christ, Nazarenes, Baptists (of all types) and Methodists (although less intensely).
The Romney v. Trump leanings of Non-Denominational Christians and Assemblies of God and to a lesser extent Presbyterians may reflect church groupings that are less likely to be in the Rust Belt and more likely to be urban or at least suburban.
Non-Denominational Churches are something of a cypher, tending to organize in suburban megachurches, tending to de-emphasize any denominational-like creed, favoring contemporary music, and not very prominent in politics. Perhaps equally important, non-denominational churches may be less distant from day to day life and have members less prone to see themselves as culturally marginalized by elites. They didn't share the tribal cultural resentment that motivated other Trump voters (such as the rural Ohio voters near where my father grew up which was thick with Trump signs at every little family farmhouse). Non-denominational churches may lean Evangelical in their theology (and disproportionately made up of former Evangelical denomination members), but they tend to emphasize the prosperity Gospel more than derision of gays and anti-abortion causes, for example.
Still, I would have been hard pressed to predict the actually observed patterns which aren't a good match to the traditional division of white Christians into mainline, Roman Catholic and Evangelical factions. Likewise, there is no coherent "high church, low church" pattern. Many denominations historically split into mainline and Evangelical denominations (Lutherans, Presbyterians, Baptists, and arguably Nazarene/Disciples of Christ) spoke with one voice in the 2016 election, rather than following the liberal or conservative lead of their denomination.
Overall, in the 2016 election, religious affiliation looks like an ancestrally informative marker illuminating other factors that were really driving electoral choices, rather than a cause for how people voted, with the clear exception of Mormons. And, indeed, sliced and diced this way, it is even hard to see the trend so obvious in other examinations of voting statistics that show racist attitudes as a critical factor in Trump support.
At a minimum, however, the linked article's conclusion that the left might benefit from more mainline church attendance seems to spit in the face of the data collected, which would seem to show that the many mainline Christians far preferred Trump to Romney. At best, one could argue that the widespread abandonment of mainline denominations in favor of a non-religious worldview, has left those who remain in mainline denominations more conservative on average (something offset by the consistently very liberal political leanings of the non-religious people who leave mainline Christianity).