When did Johnson run against Nixon?

Lyndon B. Johnson did not run against Richard Nixon in a general election. Johnson, a Democrat, became president after the assassination of John F. Kennedy in 1963 and was elected in his own right in 1964. Nixon, a Republican, later ran against Johnson's successor, Hubert Humphrey, in the 1968 presidential election. Johnson chose not to seek re-election in 1968, which allowed Nixon to win the presidency that year.