There was nothing wrong with the Rich pardon. The guy had been isolated for prosecution by a New York office that wanted a "big fish," and they refused to let him go despite an extremely weak case and the fact that the laws they wanted to prosecute him under were rewritten by the Bush Administration in the 1990s to make what Rich allegedly did completely legal. The DA wouldn't let the "big fish" go, though, and had demonstrated plenty of desire not to let the guy even have a fair trial. Despite not prosecuting anyone else for anything similar, the DA wouldn't let go of Marc Rich, and Clinton pardoned him.

Now Clinton says he wouldn't have done it, but just because it was bad politics. It damaged his reputation, like his zipper hadn't done that for him. Either the pardon was justified (I have always thought it was; every citizen should be afraid of zealous prosecutors) or it was not. You don't change your mind because people don't like the decision. You don't screw with people's lives that way.