Fascinating graph, Aqizzar. I'm kinda shocked at where some of the denominations (specifically Orthodox and Seventh-Day Adventist) fall. I would have pegged them much further into the upper-right corner. (My SO was raised Adventist, so I've gotten to hear about their particular brand of cray-cray).
I've also known some Adventists, and I'm not that surprised. There's a persistent narrative that the State is destined to become a tool of the Beast, either now or at some point in the future. This runs counter to the Christian Nation ideals of most of the other right denominations. Further, the Adventists have some exceptional beliefs that keep them from joining the fabric of the Religious Right wholesale. The disagreement over what the day of worship is, pacifism, vegetarianism, ect. All in all, they're just out there enough that the traditionals don't feel quite comfortable extending the ecumenical branch, while the rest of the religion is in line enough that they don't go all deviant and end up in UU's club.
As for Orthodox, my
spying on observations of the American Orthodox is that they're essentially carving out a niche as the reconstruction of Christianity for disillusioned evangelicals and the like. Though I am loath to admit it, the Orthodox are a lot better at what they do than certain groups of American Protestants who will remain unnamed poisondrinkerschristianidentitydominionistsprosperitytheologycharismaticsassembliesofgodreformedlutheranism and can pick these people up a lot easier than most. Ancestral Sin instead of Original Sin can get a lot of them, as well as just the general competence that comes with being the oldest remaining coherent Christian sect. If there is
any theological path to justifying something, the Orthodox found it 500 years ago. So instead of staying unhappy or leaving Christianity, a lot of these disillusioned ones gain an at least more internally consistent vision through the Orthodox. It helps that the Orthodox is so old and less involved in politics that they more or less don't map to the modern left-right spectrum, that they're super small in the US, and that they can boast about being original gangsters more than even the Catholic Church. The exception to all this is Alaska, which is filled with super reclusive old Orthodox communities who have probably all become snow cannibals by now.