The Justice Department, under the control of the Administration, is virtually by definition political and has nothing to do with Justice (the balance scales type). It has to do with imposing the law to fit the needs and interpretation of the Administration and protecting Admin. wrongdoers..
The Justice Department and the FBI (&others) should absolutely be under control of the Article 3 Judicial Section of the Constitution, not the Admin. The Congress is allowed to establish inferior courts and should find an "inferior court" for Justice and the FBI (&others)