Laws covering this retroactively can be passed and a DOJ demand for ANY material in ANY former POTUS library can be demanded.
Frankly I would prefer to BAN presidents from taking ANY working materials with them. They should be considered PUBLIC property, not theirs, and not theirs to decide what is and isn’t released.
The Library of Congress should establish separate “presidential archive” departments for each POTUS administration, and they and LAW set by Congress should dictate how access if provided. Former presidents should have NO say in it. It is not their personal property and they are no longer in authority over anything related to what they did while in office.
They should only get to take their “personal papers”, which would be letters or communications of a purely personal nature, nothing else. The materials in the Library of Congress would be available to them for any research they want to do, or have done, on the material sent there from their administration.
They should only get to take their “personal papers”
I think that is what the Presidential Library are for, the personal papers of the President, not everything his administration did.
Obama may be admitting that he was part of the unmasking since he considers the unmasking documents part of his personal papers.