When Max Eastman took exception to the idea that atheists could not fight communism, William F. Buckley Jr. argued in a 1962 Los Angeles Times editorial that “atheists are less likely than Christians (or any other religious people) to put up the only kind of a fight that is truly relevant in the age of the atom.” That is, the lack of a transcendent view of human existence leaves atheists ill-prepared to devote themselves entirely to the fight against materialistic communism. Buckley did not base this position on an assumed affinity or sympathy between atheistic communists and people, otherwise properly anti-communist, who do not believe in a deity. Rather, he believed that atheists would be uniquely vulnerable to timidity and panic in the face of apocalyptic nuclear confrontation.
For Buckley, the Christian has an advantage in this fight because communism “explicitly denies what we understand to be the roots of reality…religion, the belief in an ultimately undenying, and undeluded God.” When confronted with this ontological denial, the Christian will be possessed of a fervor that must prevent any notion of capitulation to saber rattling, while the atheist, lacking the surety of the world to come, may well bargain in order to save the only life he will have. Thus, Buckley demanded that the leaders of his country be religious men, who would rather be dead than Red.
This line of thinking helps illuminate another facet of the persistence of the unofficial religious test for office in America. Americans like to conceive of conflicts, foreign and domestic, in ultimate terms: the war on terror is a battle between Good and Evil; socialized medicine will destroy the individualist spirit of the nation forever. When conflicts are imbued with apocalyptic meaning, only someone with an apocalyptic (in the broad sense) worldview is qualified to handle them.
The continued failure of many people to accept that Barack Obama is a Christian can also be partially explained by Buckley’s argument. Obama is (wrongly) viewed by many as pushing socialism on the U.S. government—next stop will be full-fledged Stalinism, right? And of course anyone who starts down that path could not possibly be a true Christian, because otherwise he would do all he could to fight that reality-denying philosophy. For those who maintain Buckley’s notions of religious strength in the face of evil, an insufficiently religious leader will always be found lacking.
(ir)religion in america 
Thank you for your comments here, I wondered if you could describe the Christian concept of the “the atheist” – that is the characterization of atheists from something like Buckley’s point of view. It seems to me (in my amateur opinion of what I observe in Evangelical circles now) that this is a dismissive category outright which places people in the impossible position of hating all things that could have value. Would Buckley see a difference between this and a supposed “agnostic?” Or is there a more nuanced view that is not so polarized (recognizing that I am possibly creating a new dismissive category of the “evangelical”)?
That’s the big question that I am working on in my dissertation. In a couple sentences, “the atheist” is one form of shorthand used variously for non-believers, non-Christians, hard-line atheists, agnostics, and sometimes those whose Christianity is not as “right” as the speaker’s. During most of the Cold War, it was the favored term, due to the “atheistic communism” phrase. (Buckley goes in to greater detail on the association between the two in the article I discuss above.) Once the Moral Majority got going, though, it switched to “secular humanist.”
But I absolutely agree that the primary function of the term in this context is to discredit an opponent, undermine all grounds form which they might argue on, well, anything. Buckley, of course, knew the difference between atheist and agnostic philosophies; I think it’s safe to see intent in his use of one or the other.