Forget, who the FBI is or was investigating. Forget what they are investigating and how.
Remember this is the 4th election in a row that the FBI has now involved themselves in. They have to go, they can't be saved. The department must be completely dismantled, and then rebuilt with checks built into the department, if you want the department at all. FYI, there is no constitutional need for the FBI, implied or otherwise. The federal government can rely on the states to conduct investigations. At this point, it may be better that they do.