Sessions was Borked before we gave that political lynching a new verb. I don't see him taking a pass on any evidence of wrongdoing by anybody, period.
And if O'Bongo wants to see his ability to issue blanket pardons challenged in court I would love to see it. We never hashed that out with Nixon. Though years later even Bernstein, Ted Kennedy and such would say it was the right thing to do. Again, this case was about a President, not a cabinet member. One could argue a cabinet member being held to account by the normal process of justice does not warrant the level "national interest and healing" as citied in the Nixon case...and also there is the nature of the alleged crimes...Nixon's was largely on obstruction of justice, the same charge levelled at Bill Clinton...but the proceeding and result for each was different...why? In the Hillary Clinton case there is much more widespread instances of compromised national security, corruption and cronyism...on a far grander scale that Nixon, and the national security aspect of her actions are much more serious than mere obstructionism.
And if O'Bongo goes the pardon route, she is sullied forever, and he daughter will bear some of that shame. We saw the McKenna Interpretation in full play with Nixon - In 1915 Supreme Court Justice Joseph McKenna ruled that a pardon “carries an imputation of guilt; acceptance a confession of it.” (Burdick v United States) - Nixon was ruined, the pardon cemented his culpability beyond his ability to rehabilitate his reputation, Hillary Clinton would find it that way as well.
It has never been fully tested in court if a pardon can be issued before any charges are filed or any indictments made. A blanket pardon of this nature falls more into the amnesty classification.
Article 2 Section 2 states at the end about Executive powers - "...and he shall have Power to Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment."
Over the years this power has been expanded in practice to include conditional pardons, commutations, forgiveness of remissions and forfeitures, respites, and amnesties. For the latter events such as the Whiskey Rebellion, Civil War and Vietnam draft dodgers is most prominent.
The Heritage Foundation asserts that a pardon cannot be issued without a charge, but the courts have consistently refused to limit Presidential power in this area. The murkiest issue of a President pardoning himself has not yet occurred, though Nixon people did consider it, but as it looked bad every which way given our Founding and history - a President declaring himself above the law and ruling on his own case - it was not seriously pursued. That we end up with a latter day POTUS like Obama again could test that foundation.
Time will tell.