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
Vice President of the United States anticipated that the vice president would not always be available to fulfil this responsibility, the Constitution provides that the Senate may elect a President pro tempore (or "president for a time") in order to maintain the proper ordering of the legislative process. In practice, since the early 20th century, the President of the Senate rarely presides, nor does the President pro tempore. He regularly delegates the task to other Senate members. Rule XIX, which governs debate, does not authorize the vice president to participate in debate, and grants only to members of the Senate (and, upon appropriate notice, former presidents