A note from TPM Reader SL ...
All the focus seems to be on how bad second terms have been for 2-term presidents. But unless I'm mistaken, the underlying events to the scandals invariably took place in the first term (Nixon, Reagan, Clinton, Bush II). Question: is there a correlation between not being reelected and being the kind of guy who doesn't do or countenance that sort of bad behavior in the first term. 2 test cases: Carter and Bush I. Bush I would probably have had problems in the second term because he wouldn't have pardoned Weinberger et al if he hadn't been on the way out. That leaves Carter, and I suppose he a particularly morally scrupulous guy. Otherwise, it's all of a piece.
Also, it's not that the cover up is worse than the crime, or even that the cover up is what's punished and not the underlying crime. It's that the cover up keeps the investigators away from the underlying crime so it can't be prosecuted. For example, North's paper shredding; Libby's sand in Fitzgerald's eyes.
I think this is exactly right, certainly it applies to Watergate. But there's another dynamic. And that is how much these cover-ups aim not simply to avoid detection permanently, which is of course the ultimate goal, but to push exposure out past reelection. That's Watergate certainly. In a very different set of circumstances that is what Clinton's lawyers were trying to do with the Jones suit -- at least push it out past the '96 election. And I think we'll find more and more that is what happened here.