Which officials can invoke the 25th Amendment to declare a president unfit?

1. Who formally starts the process: the Vice President plus a majority of Cabinet officers

Section 4 requires the Vice President and a majority of the “principal officers of the executive departments” to send a written declaration to the President pro tempore of the Senate and the Speaker of the House that the President is “unable to discharge the powers and duties” of the presidency; when they do, the Vice President immediately assumes the powers and duties as Acting President ^{[1] [2]}. The leading legal descriptions and constitutional annotations identify those “principal officers” as Cabinet secretaries ^{[4] [1]}.

2. Congress can be the alternative body if it chooses to create one

The Amendment allows Congress to designate “such other body as Congress may by law provide” in place of the Cabinet; if Congress created that body and it acted with the Vice President, its declaration would substitute for a Cabinet majority ^{[1] [5]}. Congress has not replaced the Cabinet with such a body in practice and the scholarly sources treat the Cabinet as the operative group ^[4].

3. What happens immediately and how the President can respond

Once the Vice President and a Cabinet majority transmit their written declaration, the Vice President “shall immediately assume the powers and duties of the office as Acting President” ^{[1] [2]}. The President can then transmit a written declaration to the congressional leaders that no inability exists and resume the office—unless the Vice President and a Cabinet majority deliver a counter‑declaration within four days, which triggers a Congressional decision ^[1].

4. The Congressional check: a supermajority safeguard

If the Vice President and Cabinet counter within four days, Congress must decide within 21 days after receiving that counter‑declaration (or after it is required to assemble) whether the President is unable to discharge the duties; only a two‑thirds vote in both the House and the Senate will keep the Vice President as Acting President. If Congress fails to reach that supermajority, the President resumes office ^{[1] [6]}.

5. Sections 1–3: succession and voluntary transfers

Sections 1 and 2 affirm ordinary succession (the Vice President becomes President upon death, resignation, or removal) and set the process for filling a vacant vice presidency (President nominates, Congress confirms) ^[6]. Section 3 permits a President to voluntarily transmit a written declaration to congressional leaders that he or she is unable to perform duties and to resume the office by a subsequent declaration; several presidents have temporarily used Section 3 for planned medical procedures ^{[3] [5]}.

6. History, precedent and political reality

Scholars and official annotations stress that Section 4 has never been used to permanently remove a President; it has been debated and threatened in crises (for example during the Trump administration after January 6), but its use would be constitutionally novel and politically fraught ^{[4] [5]}. Commentators like Brookings and civic guides have urged the Vice President and Cabinet to act in extraordinary circumstances, reflecting one view of the Amendment’s intended safety valve ^{[7] [8]}. Political actors have also publicly called for invocation in contemporary disputes, showing that calls to use the Amendment often become partisan flashpoints ^{[9] [10]}.

7. Key limits and unresolved questions

The Amendment’s text is clear about who can initiate under current practice—Vice President plus a Cabinet majority or another Congress‑designated body—but it leaves open contested questions about how to interpret “unable,” what evidence suffices, and how political dynamics would affect Cabinet willingness to act; the sources note these legal and practical uncertainties ^{[1] [4]}. Available sources do not mention a definitive judicial test or a routine evidence standard for determining inability under Section 4 ^{[1] [4]}.

8. Bottom line for citizens and officials

Legally, only the Vice President acting together with a majority of the Cabinet (or a Congress‑created body) can trigger Section 4’s written declaration that makes the Vice President Acting President immediately; Congress provides the final check by requiring two‑thirds votes in both chambers to keep that status if the President contests it ^{[1] [6]}. The Amendment is designed as an extreme, constitutional safety valve; invoking it would be unprecedented in modern practice and would shift a political decision into an extraordinary constitutional process ^{[4] [3]}.