It would be decades before a Scientologist candidate has a hope in hell of winning even a state house, let alone the White House. In the last few years, thanks to South Park and 4chan, most Americans have learned all about Scientology's kooky beliefs and shady operations. The word "Xenu" has entered popular parlance. For a Scientologist to get elected President, Scientology itself would have to become more moderate, open, and mainstream, much like Mormonism did during the last century. That would require taking it out of the hands of the hucksters who are currently running it, not to mention a greater acceptance of New Age spiritualism in general, as some of Scientology's beliefs (aliens, reincarnation) fall squarely into the New Age realm. Then, and only then, would a Scientologist candidate have a reasonable shot at the presidency, and even then, he or she would still have to answer questions about his or her faith (much like JFK regarding Catholicism, and Romney regarding Mormonism). Seriously, there will probably be a Muslim President before a Scientologist one.