You’re meshing the appointed leadership with the field agents, but rank and file FBI and most of their bosses are law enforcement whose assembly line is Justice, not policy, and they’re the guys with the guns, not the creatures with the pencils.
That's only a part of it. The FBI as an institution pushes for and against legislation, and when they push they can shove. They play a meaningful role in the actual drafting of the law.
This is not like an inherently evil thing, usually their political agenda, such as it is, it to strengthen laws that make it easier for them to do their work, and push back against laws which restrain their power. They work to protect the interests of their institution, which is understandable, but that necessarily enters into the policy realm.
> You’re meshing the appointed leadership with the field agents, but rank and file FBI and most of their bosses are law enforcement whose assembly line is Justice, not policy, and they’re the guys with the guns, not the creatures with the pencils.
I'm not. When I say "the FBI", I speak of the institution as a whole. Everyone from the rank and file to the bosses.
That is not to say that appointees have no influence; they can have a lasting effect through hiring practices and other personnel actions, effects that may outlast administrations. Appointees certainly do not learn of all activities of their underlings, if only because they only have so many hours in the day to read. What they do get to read is filtered for them by those same underlings.
If the leadership is weak, uninterested or unengaged, then yes, middle management can take their stab at steering the ship (and compete with each other to do it). On the other hand, they can also just be fired if they get uppity, and if leadership has someone stepping on their toes or undermining them, well rank has it’s privileges and anyone can be replaced. Make the distinction between a working stiff with law enforcement power and a pencil pushing swamp creature with political power.
The appointees have literally no way to know how well their orders are being followed, except as by reported by those who they hope are following them.