Presidents have long claimed the authority to classify materials by dint of the president being the nation’s chief executive and commander in chief — the only official vested under Article II of the Constitution with “the executive power.”
Presidents have long claimed the authority to classify materials by dint of the president being the nation’s chief executive and commander in chief — the only official vested under Article II of the Constitution with “the executive power.”
And they are U.S. Supreme Court certified as having that power as a constitutional grant.
https://www.loc.gov/item/usrep484518/
Dep't of Navy v. Egan, 484 U.S. 518, 526-27 (1988)
The Court of Appeals' majority stated: "The absence of any statutory provision precluding appellate review of security clearance denials in section 7512 removals creates a strong presumption in favor of appellate review," citing Abbott Laboratories v. Gardner, 387 U. S. 136, 141 (1967). 802 F. 2d, at 1569. One perhaps may accept this as a general proposition of administrative law, but the proposition is not without limit, and it runs aground when it encounters concerns of national security, as in this case, where the grant of security clearance to a particular employee, a sensitive and inherently discretionary judgment call, is committed by law to the appropriate agency of the Executive Branch.The President, after all, is the "Commander in Chief of the Army and Navy of the United States." U. S. Const., Art. II, § 2. His authority to classify and control access to information bearing on national security and to determine whether an individual is sufficiently trustworthy to occupy a position in the Executive Branch that will give that person access to such information flows primarily from this constitutional investment of power in the President and exists quite apart from any explicit congressional grant. See Cafeteria Workers v. McElroy, 367 U. S. 886, 890 (1961). This Court has recognized the Government's "compelling interest" in withholding national security information from unauthorized persons in the course of executive business. Snepp v. United States, 444 U. S. 507, 509, n. 3 (1980). See also United States v. Robel, 389 U. S. 258, 267 (1967); United States v. Reynolds, 345 U. S. 1, 10 (1953); Totten v. United States, 92 U. S. 105, 106 (1876). The authority to protect such information falls on the President as head of the Executive Branch and as Commander in Chief.
The President's grant of the entirety of the Execuive power comes via direct grant in the Constitution and is plenary. E.O. 13526, Classified National Security Information, provides guidance to federal agencies on classification and declassification of information. The Office of the President is not a Federal agancy. The President does not issue such guidance to himself, and it does not bind himself or any subsequent President.
Congressional Research Service Report, Procedures for Declassifying Intelligence of Public Interest, August 4, 2022
Executive Order (E.O.) 13526, Classified National Security Information, signed by President Barack Obama on December 29, 2009, provides guidance to federal agencies on classification and declassification of information.[...]
The President has the authority to declassify documents in the public interest that originated in any department or agency of the executive branch.