What Are the Lessons Learned From J. Edgar Hoover?

The Republican House has promised that they are launching a massive investigation into the FBI for the first time in half a decade. So what do we learn from studying this man so closely and the institution he built? Well, I think today's FBI still bears the stamp of J. Edgar Hoover in all sorts of ways. But we have this really interesting reversal, where Republicans and conservatives have turned on the FBI.