Tzadik?

A reader writes:

Is Gelernter absolutely insane? I grew up in the Orthodox community and attended numerous Yeshivot, and the word Tzadik was reserved for the most learned, most pious, and most sincere people in our community. It's a word reserved for Rebbe's and Heads of Yeshivot. For great leaders in the Jewish community. No one would ever dream of calling someone a tzadik if they had called their wife the c-word in front of reporters. He might be a really good guy, but we have a special word for that in Judaism too. A Mensch. And you can make mistakes and still be a mensch. McCain hasn't been much one of those during this election, but I wouldn't mind saying that over his life he's been a pretty decent guy. But a tzadik?