Political decisions as the product of religious faith

The current Chronicle Review includes an interesting article by Hillsdale prof D.G. Hart suggesting that the widespread support of Donald Trump among "evangelicals" reveals longstanding sloppiness in political scientists' reliance on "evangelicals" as a relevant category.  He notes that the broad category ignores the extent to which local congregations are isolated from each other because of deep religious differences:

[I]f evangelical identity was so thin that it could not overcome realities that prevented Pentecostals from worshiping with Presbyterians, how useful was it to explain the way believers participated in electoral politics? Both a Baptist and a Methodist might vote for the same Republican presidential candidate, but was that the product of religion? Too much of the literature on evangelicals and politics said, 'Yes.'

Hart suggests moving away from evangelicalism as a category and looking instead to church membership, noting data showing that Protestants who attend church regularly are much less likely to vote for Trump than are people who self-identify as "born again." More broadly, he wonders whether scholars "should simply take religion less seriously" in explaining a person's ideas or actions.  He cites Fintan O'Toole's work arguing that religion was not the chief factor alienating Protestants and Catholics in Northern Ireland.

There has been much hand-wringing over the breakdown of commitment to the core principles that have guided evangelicals' political engagement. Maybe that commitment was more illusory than we thought, and maybe the perception of guiding principles reflects a past convergence of motivations that had less to do with faith than previously assumed.  In other words, maybe "evangelicals" look more like "Catholics?"