While Nixon famously originated the Watergate scandal, it is Hillary Clinton that has mastered the art of creating and escaping all manner of political impropriety.
In 1993 it was alleged that Hillary Clinton had orchestrated the firing of otherwise upstanding employees of the White House Travel Office to make room for political friends. The affair was dubbed "Travelgate". In 1994 it was revealed that Hillary had made a whooping 100x return on investment in cattle futures in ten months time. The event would prompt allegations of impropriety and bribery that would never be investigated. Following the Lewinsky scandal involving sexual misdeeds of her husband while President, Hillary has been accused of orchestrating the intitmadtion and harassment of women who would later accuse her husband of rape.
That is to say nothing of the more recent Benghazi and Email server scandals; the latter of which Hillary is currently under FBI investigation for. They'll need all the luck they can get, Hillary is the Houdini of political escape artistry.