To a certain extent, Justice, as any other activity of government, has a political (or at least policy) component. Attorneys General have agendas - or emphases - that pervade the Department. They might, for example, emphasize organized crime, white collar crime, or gang violence. They might emphasize hate crimes or focus on voting rights. This, however, is more nuance or flavor than politics.
The current Attorney General, however, has taken a sledgehammer to the concept of independence. I give him credit for recusing himself from the Russia inquiry, but... even there, he involved himself in the firing of FBI Director Comey. But it is not so much the Attorney General but the Tyro-in-Chief who doesn't understand the concept
of independence (or many other legal concepts, frankly). Nor does Congress. Today Senators Grassley and Graham perverted the process again by seeking an investigation from Justice
over the Steele dossier. Similarly, other congresscritters have sought to use their influence to reopen or open the inquiry regarding Hillary Clinton - beyond the millions of dollars already wasted on their own.
This is a very disturbing issue, and threatens the entire legal system.
As I was finalizing this, new issues have come up: Clinton Foundation investigated by Justice Department