The idea that what Blagojevich did is somehow worse than for example, Christie's wife making $475,000 working for a company that has special deals with New Jersey's pension plan is absurd.
It's a question of degree. There were multiple instances where Blago was recorded saying to a group (eg Children's Memorial Hospital) that he would only sign a document releasing millions of dollars of properly appropriated funds if there was a substantial donation (50K$ was typical). That type of quid pro quo for an official act crosses the line.
