Defending a pathological liar only works if the defender believes the lies/is pathological too or it's futile. What does futile buy? Why?

Before we play the "pathological liar" card we better first recall the career and cover ups of madame secretary. I know that her reputation is sterling and beyond all reproach, but it's only because we can't find most of it out there. To her credit, she learned something in 1974. If Nixon  had destroyed the tapes, he would never have had to resign.