Commentary Congress proposed the Constitution’s 25th Amendment in 1965, and state legislatures finished ratifying it in 1967. Because of widespread doubts about President Joe Biden’s mental condition, the amendment has gained attention as a potential vehicle for transferring his authority to the vice president. The 25th Amendment has four sections. Section 1 says that when the presidency becomes vacant, the vice president becomes president rather than merely “acting president.” Section 2 outlines how to choose a replacement when the office of vice president becomes vacant. This procedure has been used twice, resulting in the appointments of Gerald Ford and Nelson Rockefeller. Section 3 describes how a president declares himself “unable to discharge the powers and duties of his office,” how he devolves power to the vice president, and how he re-takes the reins when the disability has passed. Presidents Ronald Reagan and George W. Bush both used this procedure before …