Vice President of the United States the Twenty-fifth Amendment established a procedure for filling such a vacancy: This procedure has been implemented twice since the amendment came into force. The first instance occurred in 1973 following the October 10 resignation of Spiro Agnew, when Gerald Ford was nominated by President Richard Nixon and confirmed by Congress. The second occurred 10 months later following Ford's August 9, 1974 accession to the presidency upon Nixon's resignation, when Nelson Rockefeller was nominated by President Ford and confirmed by Congress. Had it not been for this new constitutional mechanism, the vice presidency would have remained vacant after Agnew's resignation and
President-elect of the United States "enter upon the execution" of their office, but they are already president from the start of their term. The president-elect and vice president-elect receive mandatory protection from the United States Secret Service. Since the 1968 assassination of Robert F. Kennedy, major-party candidates also receive such protection during the election campaign. During the presidential transition period, the president-elect's running mate is known as the Vice President-elect. As with the title President-elect, it applies to the person determined by the GSA Administrator to be the apparent successful candidate for the office of Vice President after the general election. If the Vice President-elect