What happens if a presidential candidate dies before the election?

The rules governing what happens if a presidential candidate dies depend heavily on timing. There are four distinct phases - before the convention, after the nomination, after Election Day, and after inauguration - and each has different legal or party-rule machinery.

If a candidate dies during the primary season, before the party convention, the primary process simply continues with the remaining candidates. Delegates pledged to the deceased candidate are typically released to vote for another contender at the convention, following party rules.

If the nominee dies after the convention but before Election Day, the party national committee has authority under party rules to pick a replacement. The Republican National Committee may convene under Rule 9 to fill the vacancy; the Democratic National Committee has parallel procedures. In many states the ballot is already printed with the original nominee's name, but the replacement would receive that candidate's electoral votes.

If the election has occurred but the winner dies before the Electoral College votes in December, the situation becomes constitutionally complex. Electors in most states would vote for the deceased candidate's running mate, or for a party-designated replacement. A historical parallel: Horace Greeley, the 1872 presidential candidate, died between Election Day and the Electoral College meeting; his electors scattered their votes among several Democrats. In 1912, Republican vice-presidential nominee James S. Sherman died just before Election Day; the party's electors cast VP votes for Columbia University President Nicholas Murray Butler instead.

After the Electoral College votes, the 20th Amendment (Section 3) provides that if the president-elect dies before January 20, the vice president-elect becomes president at inauguration. Once a president is in office, the 25th Amendment governs succession: the vice president takes over.