“If the POTUS discloses classified information then it, from that point, becomes unclassified.”
That is incorrect. The POTUS CANNOT unilaterally change the classification on anything classified. The ORIGINATOR of the classified information is the only one that can downgrade it. The originator can be a person (usually the person who sourced it) or the agency with which the information derived, normally it’s the agency. Obama is guilty, period.
“The POTUS CANNOT unilaterally change the classification on anything classified. The ORIGINATOR of the classified information is the only one that can downgrade it.”
No, that is not fully correct. The originator, OR anyone with a higher classification authority than the originator can downgrade it.
The President, as head of the Executive branch, has the highest possible classification authority, and is actually the one from whom all other classification authority is delegated, so he can override any subordinate official or agency in matters of classification. He makes the rules they must follow, but he is not bound by those rules himself.
From EO12333 (and as amended by other Presidential EOs): "For that purpose, by virtue of the authority vested in me by the Constitution and statutes of the United States of America, including the National Security Act of 1947, as amended, and as President of the United States of America, in order to provide for the effective conduct of United States intelligence activities and the protection of constitutional rights, it is hereby ordered as follows:"
Once again, the President has the ultimate classification authority, but may delegate the authority and responsibility for classifying and declassifying material to organizations and agencies under him within the executive branch. Each agency head may further delegate authority to classify material to a limited group of department heads.
The ORIGINAL classification authority only prevents someone in one department or agency from changing the classification of material from another department or agency. Thus, the DoS cannot change the classification of material classified by the DoD.
The executive agencies, including DoS, DoD, and Intell all work for the POTUS. POTUS is the ultimate OCA.