The term "corruption" is frequently applied to the actions of politicians for lack of a better term to describe their questionable behavior.  The SCOTUS decision provides a very specific and rather narrow legal definition to the term.  As this editorial highlights, it's a definition which will limit successful prosecution to only the most egregious and tansparent actions by office holders.  

Former Governor Kitzhaber is unlikely to face any prosecution, but will be remembered by that famous cliche' "there's no fool like an old fool" for allowing his girlfriend to misuse the power of the Governor's office.  ....as embarrassing as is, it sure beats going to prison.