Emanuel is by my count the fifth WH Chief of Staff who previously served in elected office. Two (Panetta and Howard Baker) retired on their own terms; two others, Sherman Adams and John Sununu, resigned after scandal, but odds are in both cases the scandal was 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.