... I think that Romney's speech will serve at least in part as an anvil on which one of the more surprising alliances in American politics will be hammered out: the one between conservative Catholics and Protestants. It wasn't so long ago that the idea of an Evangelical-Catholic alliance would have been anathema to both sides ... That changed beginning in the 1970s, when conservatives from both traditions decided that the forces of secularism were a greater threat than either Rome or heresy. The alliance, however, is not an entirely easy one. (Witness for example, the furor caused by Francis Beckwith's conversion from Evangelicalism to Catholicism.) I suspect that not too far below the surface of the Religious Right one will find a deep-seated theological ambivalence: Did the religious conservatives sell-out theologically by clasping hands across what had been the ultimate divide in American religious politics?
Part of this tension has been managed by the promotion of "The Great Tradition," a somewhat fictitious creation, that like 'Judeo-Christian culture," provides a coping mechanism for the cognitive dissonance created by the contradictory pulls of politics and theology. In effect, it allows Protestant and Catholic intellectuals to tell themselves, "I didn't sell out my beliefs for control of Congress; after all we both believe in Nicea and Chalcedon." In a world of un-conflicted sectarian competition, I suspect that the Mormon rejection of the creeds didn't matter all that much. Sure, it meant that Mormon theology was wrong, but everyone else's theology was wrong too, so there was no special Mormon problem. Likewise, Mormon rejection of the creeds didn't matter all that much when Ike presided over a culturally self-confident and complacent Protestantism. "Letting Mormons sit at the table," the Protestants in effect told themselves, "doesn't say anything about Protestantism because everyone understands that we wield ultimate control." (Hence, for example, Mormon apostle Ezra Taft Benson -- pictured at his swearing in left -- could serve in Ike's cabinet without the sky falling for Evangelicals.) Not so in a world where Protestant hegemony is challenged by the forces of godlessness.
Hence, I suspect that the reason why many within the Religious Right want to deny Romney (or any other Mormon) the Presidency is because Mormonism is an important theological marker that legitimizes the other theological compromises that have made the coalition possible. "Sure, we'll work with the Papists," the conservative Evangelical subconscious can say to itself, "but the Mormons are one theological compromise too far. I am not a theological sell-out because while I will accept Mormon votes, I will not accept a Mormon leader." Soft-bigotry against Mormons facilitates broader theological cooperation.
As a Mormon, I have to say that living on the anvil where the concerns of others get hammered out can be a bit uncomfortable. On the other hand, I take solace in the fact that much of the time it probably really isn't about my religion.
This analysis makes a lot of sense; I only object to note of self-pity at the end. Just because evangelicals (and Catholics, to a lesser extent) are using Mormonism as a marker to legitimize their own theological compromises doesn't mean it isn't a reasonable marker to use. It isn't only about Oman's religion, but it is about it to a great extent: Mormonism is a useful marker of how far ecumenism can go (and how far it can't) precisely because there are much, much deeper theological commonalities between, say, the Vatican and the Southern Baptist Convention than between either body and the the LDS Church. And while it's true that Mormons get more attention, and hostility, than other similarly-heterodox strands of American religion, they're at least partially victims of their own success. If the Jehovah's Witnesses, say, were doing as well as the Mormons are at winning converts, their tenets might be playing the same sort of "here's where the Great Tradition stops" role in debates over ecumenical cooperation. But they aren't, so they don't.
As an outside observer, it seems to me that Mormonism has a divided soul - there's a yearning for acceptance within the firmament of Christianity (and a hint of self-pity concerning other Christians' unwillingness to welcome them with open arms), combined with a pride in everything that makes the Latter-Day Saints unique. I'm inclined to think the latter is the healthier sentiment for members of a young and rising faith. Attention, and the hostility that comes with it, is the price of being a successful religion, as the larger history of Christianity's rise attests: You don't see Christopher Hitchens writing polemics against the Mithraists or the cult of Isis, after all.