Such a retard. 25A is HARDER to achieve than impeachment, as it requires not only more than 2/3 votes in congress, but also a majority of the President's cabinet:

Whenever the Vice President and a majority of either the principal officers of the executive departments or of such other body as Congress may by law provide, transmit to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Vice President shall immediately assume the powers and duties of the office as Acting President.

Thereafter, when the President transmits to the President pro tempore of the Senate and the Speaker of the House of Representatives his written declaration that no inability exists, he shall resume the powers and duties of his office unless the Vice President and a majority of either the principal officers of the executive department or of such other body as Congress may by law provide, transmit within four days to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office. Thereupon Congress shall decide the issue, assembling within forty-eight hours for that purpose if not in session. If the Congress, within twenty-one days after receipt of the latter written declaration, or, if Congress is not in session, within twenty-one days after Congress is required to assemble, determines by two-thirds vote of both Houses that the President is unable to discharge the powers and duties of his office, the Vice President shall continue to discharge the same as Acting President; otherwise, the President shall resume the powers and duties of his office.

So, VP & cabinet can invoke it. But if the president says there is no issue, "he shall resume the powers and duties of his office". Then the hurdle they have to clear is "Vice President and a majority of either the principal officers of the executive department", and then to congress, where "by two-thirds vote of both Houses that the President is unable to discharge the powers and duties of his office".

So impeachment and removal/conviction requires simple house majority and over 2/3 of senate. 25A requires VP, majority of cabinet, over 2/3 of house, and over 2/3 of senate.