The United States presidential election of 1804 pitted incumbent Democratic-Republican President Thomas Jefferson against Federalist Charles Cotesworth Pinckney. Jefferson easily defeated Pinckney in the first presidential election conducted following the ratification of the Twelfth Amendment to the United States Constitution.
Under the rules of the Twelfth Amendment, presidential electors were required to specify in their votes their choice for President and Vice President; previously, electors voted only for President, with the person who came in second becoming the Vice President. George Clinton was elected Vice President and went on to serve under both Jefferson and his successor, James Madison.
Jefferson's 45.6 percentage point victory margin remains the highest victory margin in a presidential election in which there were multiple major party candidates.1