The two former DOJ officials that wrote Comey has "damaged democracy" failed to mention that it is unprecedented that any former presidential nominee has ever been under federal investigation.  It is also unprecedented that the Attorney General meet with the husband of the person under investigation.  

Director Comey's Deputy Director was tasked with overseeing the investigation of Clinton.  Comey's had was forced when it was learned that his Deputy Director's wife received large donations for her state campaign from one of Clinton's closest allies, Governor Terry McAuliffe who is also under FBI investigation for receiving campaign funds from a Chinese businessman.  (article in Wall Street Journal).
It is also obvious that State Dept. documents must have been found on the laptop belonging to Clinton's top aid, Huma Abedin and her husband Anthony Weiner.  Even if Clinton is elected, the investigations will continue.  The rule of law implies that every citizen is subject to the law.