Sherman Adams and John Sununu resigned after scandal but...in both cases the scandal was [probably] a result of the enemies created by their style in office rather than a result of particular ethical shortcomings (I'm confident that's true of Sununu, but I'm only really guessing on Adams -- I don't know the history well enough to say). I think it's an fairly safe prediction that Rahm ends up more like Adams/Sununu than like Panetta/H. Baker. He's most likely an excellent chief of staff, but odds are he's making plenty of enemies, and when he does something dumb they'll all pounce. Just the nature of the job.Making plenty of enemies? Check. Leaving to run for office, instead of under a (deserved or not) ethical cloud? Uh, missed that one.
So, what can I say about it? I can think of two things. One is the possibility that something's changed, so that strong, politically independent White House Chiefs of Staff no longer absorb potential anger at the president, thereby leaving them with few friends, many enemies, and ready for the trash heap at the first whisper of scandal. A second is that the dynamics were the same, but that Rahm Emanuel is a far superior pol compared to Adams and Sununu, and managed to survive unscathed through brilliant maneuvering. Or, Rahm was heading for the demise I expected, but saw it coming and jumped before the process could really proceed very far. You won't be surprised to learn that I believe the correct answer is #3. I'm not saying he was about to be ousted, at all; I'm saying that the normal instinct for most White House Chiefs of Staff is to try to hang on to power as long as possible, and that Rahm, in choosing not to do so, avoided being forced out down the road.
By the way, I'm looking at the list of WH Chiefs of Staff, and just from memory I believe the only ones who left on their own terms outside of the waning months of an expiring presidency were James Baker (the first time, when he swapped jobs with Don Regan), Leon Pannetta, and Erskine Bowles. I think it's generally not a bad idea for the job to rotate every couple of years, following the Clinton administration's example, and perhaps that's what's going on here. Of course, it's always possible that it will later be revealed that Rahm was in fact forced out and given the mayoral campaign as a face-saving thing, but otherwise I think it's a generally positive development. One that I, obviously, did not see coming at all.