<P> In case of the removal of the President from office or of his death or resignation, the said office shall devolve on the Vice President . In case of the inability of the President to discharge the powers and duties of the said office, the said powers and duties shall devolve on the Vice President, until the inability be removed . The Congress may by law provide for the case of removal, death, resignation or inability, both of the President and Vice President, declaring what officer shall then be President, or, in case of inability, act as President, and such officer shall be or act as President accordingly, until a President shall be elected or, in case of inability, until the inability shall be earlier removed . The commencement and termination of any inability shall be determined by such method as Congress shall by law provide . </P> <P> Senators raised concerns that the Congress could either abuse such authority or neglect to enact any such legislation after the adoption of this proposal . Tennessee Senator Estes Kefauver, the Chairman of the Senate Judiciary Committee's Subcommittee on Constitutional Amendments, a long - time advocate for addressing the disability question, spearheaded the effort until he died in August 1963 . Senator Keating was defeated in the 1964 election, but Senator Roman Hruska of Nebraska took up Keating's cause as a new member of the Subcommittee on Constitutional Amendments . </P> <P> By the 1960s, medical advances had made increasingly plausible the scenario of an injured or ill president living a long time while incapacitated . The assassination of John F. Kennedy demonstrated to policymakers of the need for a clear procedure for determining presidential disability, especially in the context of the Cold War . The new president, Lyndon B. Johnson, had once suffered a heart attack and--with the office of vice president to remain vacant until the next term began on January 20, 1965--the next two people in the line of succession were the 71 - year - old Speaker of the House John McCormack and the 86 - year - old Senate President pro tempore Carl Hayden . Senator Birch Bayh succeeded Kefauver as Chairman of the Subcommittee on Constitutional Amendments and set about advocating for a detailed amendment dealing with presidential disability . </P> <P> On January 6, 1965, Senator Birch Bayh proposed S.J. Res. 1 in the Senate and Representative Emanuel Celler (Chairman of the House Judiciary Committee) proposed H.J. Res. 1 in the House of Representatives . Their proposal specified the process by which a President could be declared "unable to discharge the powers and duties of his office", thereby making the vice president an Acting President, and how the President could regain the powers of his office . Also, their proposal provided a way to fill a vacancy in the office of vice president before the next presidential election . This was as opposed to the Keating--Kefauver proposal, which neither provided for filling a vacancy in the office of vice president prior to the next presidential election nor provided a process for determining presidential disability . In 1964, the American Bar Association endorsed the type of proposal which Bayh and Celler advocated . On January 28, 1965, President Johnson endorsed S.J. Res. 1 in a statement to Congress . Their proposal received bipartisan support . </P>

What is the 25th amendment to the constitution say