Impaired functioning/personal pain is not always easy for the casual observer to see. As you stated in a prior post, studies of interactions in personal settings are necessary for a firm diagnosis. However, this does not mean that observant individuals cannot pick up on abnormal reactions. Those who watch an individual carefully over a number of years are very often able to ascertain specifics that trigger various behaviors. It is actually easier to say someone seems immoral or he/she simply has political motives.
Many bible fundamentalists refuse to accomodate the concept of psychological deficiencies or abnormalities, preferring to say sin is sin.
Perhaps it only matters if we want to believe someone can be "cured." But for that, the client would have to acknowledge a problem. In this case, it is highly doubtful that would happen because it would seem unlikely there would be a base of support for change.
By the way, can you recall backwards the names of the U.S. presidents? ;)
What about total lack of personal pain that other people might feel about their serious failures and shortcomings? Wouldn't that indicate a sociopath?