"And third,
there are certain materials that presidents cannot classify and declassify at will. One such category of material is the identity of spies."
Another is nuclear secrets. The Atomic Energy Acts of 1946 and 1954 produced an even stranger category of classified knowledge. Anything related to the production or use of nuclear weapons and nuclear power is inherently classified, and Trump could utter whatever words he pleased yet still be in possession of classified material. Where are our nuclear warheads? What tricks have we developed to make sure they work? This information is “born secret” no matter who produces it."
Fan letters and snapshots are one matter, and launch codes are another—and here the details of classification might decide just how much trouble Trump is in.
www.theatlantic.com