There's a piece in The New Republic, Mormonism’s Surprisingly Deep Affinity For Progressive Politics. It's interesting, but I think that the niche for these sorts of pieces relies on the reality that there's a deep lack of interest in American history on the part of the moderately educated public. Many of the "trends" or "surprises" we see today can actually be understood and made more explicable with a marginal amount of historical knowledge, something that came home to me when I began to read some American history in depth and detail ~2008. The first thing to recall about Mormons and politics is that a greater proportion of Utah's vote went to Franklin Roosevelt than in his home state of New York in 1932. Utah had a higher rate of voting for socialist Eugene Debs in 1912 than the national average. This can be explained by simple materialism. In the early 20th century Utah was a poor state which benefited from federal public works programs which developed and subsidized its economy. Second, there are deep historical reasons why the conservatism of American Mormons today may be less than alien to American progressivism. This is part of what I call the "Dark History" or "Forgotten History" of the modern era. By this,
I mean that because of the emphasis on explicit ethnicity (e.g., Jews, Irish Catholics, etc.) and race in the modern discourse we forget the deep fissures between the Anglo folkways at the American Founding, which persisted down in a very salient manner up to the Civil War.
One of those folkways is "Greater New England," which stretches from New England proper to the Upper Midwest, and assimilated into its purview Protestant Germans and Scandinavians in the 19th century. As I have noted before the one descendant of Greater New England which is part of "Red America" is Mormon America. Despite the confluence of values and interests between Mormons and Southern Anglos, there is a deep fissure of sensibility which almost certainly ties back to the fact that the cultural template of Mormon America goes back to the Yankees who founded it, and the Northern European immigrants who were assimilated to it. Mormonism was one of the "-isms" which the Southern intellectual class abhorred in the years before the Civil War, and the Mormon conflict with transplanted Southerners in Missouri and southern Illinois took the form of a literal cultural civil war, prefiguring the "Blood Kansas" of later years. The politics of Michael Dukakis and Mitt Romney are very different, but in their affect there are profound similarities. Likely this is a coincidence, but it may also reflect the old emphasis on efficiency and technocratic order which has deep roots in the scions of Puritan America, a flinty aversion to bombast and charisma which would never go down well in the South.