The 25th Amendment, ratified in 1967, was primarily designed to address presidential succession and disability (e.g., a President undergoing surgery). However, Section 4 offers a mechanism to temporarily remove a President who is deemed "unable to discharge the powers and duties of his office," a scenario that some interpret to include mental incapacitation or profound unfitness.
How Section 4 Works
Initiation: The Vice President and a majority of the Cabinet must formally notify the leaders of the House and Senate that the President is unable to perform their duties.
Immediate Effect: The Vice President immediately assumes the powers and duties of the office as Acting President.
President's Return: The President can submit a written declaration to Congress stating that no inability exists, thus resuming their powers.
The Congressional Test: If the Vice President and a Cabinet majority disagree with the President's declaration (insisting the President remains incapacitated), they must re-submit their declaration to Congress within four days. Congress then has a limited time to act.
The High Bar: For the Acting President to permanently retain power, both the House and the Senate must vote by a two-thirds majority to affirm that the President is, in fact, unable to discharge the duties of the office.
The Polarization Problem
While Section 4 effectively bypasses the House impeachment and Senate trial procedure (which focuses on "high Crimes and Misdemeanors"), the final vote still requires an extremely high political consensus—a two-thirds majority in both chambers—making it an almost insurmountable hurdle in a highly polarized environment:
Political Loyalty: In the scenario where the President's party controls the Senate, achieving a two-thirds majority in the Senate (67 votes) is arguably more difficult than achieving it in an impeachment trial. Senators would be forced to vote against their party's sitting leader by declaring them literally unfit for office, a more direct repudiation than a vote for "high crimes."
Cabinet Dependence: The process requires the Vice President and a majority of the Cabinet to agree. Cabinet members are appointed by the President and usually owe their position and political loyalty to them. This makes the initial trigger mechanism highly dependent on an internal schism within the Executive Branch.
The "Inability" Standard: Unlike impeachment, which uses the legally defined standard of "Treason, Bribery, or other high Crimes and Misdemeanors," the 25th Amendment uses the vaguer standard of "unable to discharge the powers and duties." In a polarized environment, opponents would argue this standard is met, while allies would argue it is not, turning the medical or psychological question into a highly charged political judgment.
The 25th Amendment is a constitutional escape valve designed for crises of capacity, but the final requirement for a two-thirds vote in both the House and Senate means that, just like the impeachment trial, it is practically unusable when a powerful faction of Congress (especially the President's own party) remains highly unified and loyal.