Who does this James Comey think he is, J. Edgar Hoover?
Hoover had taken the precaution of digging DEEPLY on every person who assumed the presidency, or was a serious contender, and having enough dirt to effectively hold a sword over their heads, should they try to interfere with the activities of the FBI. This gave Hoover INCOMPARABLE power over the decades he was in office.
The FBI was started by a progressive era homo. It is still true to its roots