Should presidential candidates be given a psychopath test?

Psychopaths constitute only a tiny percentage of humans but disproportionately occupy positions of political and financial power. For that stunning and I’m sure hard-won insight, this book (“The Psychopath Test,” by Jon Ronson) wins the 2011 Statement of Obvious Banality award. But the book does raise an interesting question: Is there a way to require or pressure major federal and state political candidates — for president, Congress, governor, etc. — to take a personality inventory that would reveal psychopath/sociopath tendencies?  I realize the mere suggestion of such a requirement has all sorts of civil liberties implications, and the political hurdles may be all but insurmountable. (I’d love to see the congressional debate about such a bill on CSPAN, though.)  But those difficulties are part of the reason I find the question/suggestion interesting. Society has a clear interest in not electing a true psychopath president; presidential candidates, on the other hand, don’t lose all privacy rights, just for wanting the world’s most powerful position and 24/7 access to the football that could launch thermonuclear Armageddon. But do they retain the right to conceal psychopathy, an almost total lack of empathy manifested by the absence of what most people call a conscience, often hidden by high intelligence and a winning personality? This thought experiment is now in your court.