There is an ethical basus fir a non-politicized DOJ.
Which is what everyone wanted under Holder.
And exactly what Bannon said we should have, twice.
For a best non-politicized DOJ, please see the checks and balances in the Constitution.
The president is CIC of the executive branch.
The president's powers are checked by presidential elections every four years and by the powers of Congress to impeach the president.
What we have right now is a politicized and unethical DOJ precisely because the DOJ has become unconstitutionally untethered from the executive branch.