At the start of the conservative movement, William F. Buckley his colleagues at the National Review developed a standard explanation for the presence of evil in the world. Evil, they said, comes from attempts to create God's kingdom on earth--to "immanentize the eschaton," as they put it.
This criticism was supposed to explain why both communists--who wanted to create a worker's paradise--and liberals, who believed in applying reason and pragmatism to improve man's estate on earth, were leading the world towards godless tyranny. It was a unified theory of evil, which conveniently allowed conservatives to conflate their two greatest enemies.
Conservatives venerate this principle to this very day. For example, Jonah Goldberg's book Liberal Fascism insists that liberalism is totalitarianism simply because it believes in man's ability to make the world better through reason. In other words, liberalism is fascism because it immanentizes.
But, in the print edition of The New Republic, Damon Linker's superb review of Wayward Christian Soldiers: Freeing the Gospel from Political Captivity, highlights how George W. Bush--by applying his starkly Manichaean worldview to American politics--has come close to being a rabid immanentizer himself:
Consider Bush's speech at Ellis Island on the first anniversary of the September 11 attacks. In his remarks, the president described the United States as the "hope of all mankind" and asserted that this "hope still lights our way. And the light shines in the darkness. And the darkness will not overcome it." Marsh bristles at this passage, which alludes to the prologue to the Gospel of John but modifies its message in a crucially important respect.
Whereas the New Testament describes God as the light that will not be overcome by the darkness that surrounds it, Bush ascribed divine agency to America. For Marsh, this substitution is unforgivable--nothing less than the idolatrous "identification of the United States with Christian revelation."
By identifying American nationalism with God's will, and insisting that we are locked in an apocalyptic battle with evil, George W. Bush has committed something akin to the very heresy that conservatives call the root of all evil. And it's not just Bush. This Manichaean, good-versus-evil worldview has been integral to the conservative movement since Buckley founded National Review. (Check out Peter Scoblic's U.S. vs Them for a closer look at this phenomenon.)
So conservative moralism doesn't just obscure reality, it obscures morality as well.