Who becomes president if the president cannot serve?

#What the Constitution says

Article II originally said that if a president left office, “the Same shall devolve on the Vice President.” People debated whether that meant the office or only its powers. When William Henry Harrison died on April 4, 1841, Vice President John Tyler took the presidential oath and treated himself as president, and Congress implicitly accepted that. The Twenty-fifth Amendment, ratified on February 10, 1967, put the answer in the text: the vice president “shall become President.”

#The order Congress set

Article II lets Congress decide who acts as president when both the president and the vice president are gone. Congress has set three different orders. The 1792 law named the president pro tempore and then the speaker. The 1886 law moved to Cabinet officers. The 1947 law, now at 3 U.S.C. § 19, puts the speaker first, then the president pro tempore, then the Cabinet.

The law has conditions. The speaker and the president pro tempore must resign their posts and their seats before acting. Cabinet officers must have been confirmed by the Senate and cannot be under impeachment by the House. Everyone named in the law must be eligible for the presidency under the Constitution.

#How long someone acts as president

A speaker or president pro tempore generally acts until the current term ends. A Cabinet officer also serves until the term ends, “but not after a qualified and prior-entitled individual is able to act.” That means a newly chosen speaker or president pro tempore could take over from a Cabinet officer.

#When a president is temporarily unable to serve

• Section 3: the president sends a written declaration to the president pro tempore and the speaker, and the vice president becomes acting president until the president sends a second declaration. A CRS report updated in July 2024 lists uses in 1985, 2002, 2007 and 2021, all during medical procedures with anesthesia or sedation. The 1985 letter did not cite the amendment by name.
• Section 4: the vice president and a majority of the principal officers of the executive departments, or another body Congress sets by law, declare the president unable to serve. If the president disputes it, Congress decides within set deadlines, and keeping the president out takes a “two-thirds vote of both Houses.” The same report says Section 4 had not been activated since 1967.

#The empty vice presidency: 1973–1974

Before 1967, nothing in the Constitution filled a vacant vice presidency, and the office had been vacant on 16 occasions. Section 2 of the amendment changed that, and it was first used within seven years. Vice President Spiro Agnew resigned on October 10, 1973. Two days later, President Richard Nixon nominated House Minority Leader Gerald Ford, who was confirmed and sworn in on December 6. When Nixon resigned on August 9, 1974, Ford took the presidential oath. He then nominated Nelson Rockefeller, who was confirmed and sworn in on December 19. For the rest of that term, neither person in the top two offices had been chosen for them by electors.