<P> Under the Constitution , the vice president serves as President of the Senate . He or she may vote in the Senate ( ex officio , for he or she is not an elected member of the Senate ) in the case of a tie , but is not required to . For much of the nation 's history the task of presiding over Senate sessions was one of the vice president 's principal duties ( the other being to receive from the states the tally of electoral ballots cast for president and vice president and to open the certificates `` in the Presence of the Senate and House of Representatives , '' so that the total votes could be counted ) . Since the 1950s , vice presidents have presided over few Senate debates . Instead , they have usually presided only on ceremonial occasions , such as joint sessions , or at times to announce the result of significant legislation or nomination , or when a tie vote on an important issue is anticipated . </P>
<P> Under the Constitution , the vice president serves as President of the Senate . He or she may vote in the Senate ( ex officio , for he or she is not an elected member of the Senate ) in the case of a tie , but is not required to . For much of the nation 's history the task of presiding over Senate sessions was one of the vice president 's principal duties ( the other being to receive from the states the tally of electoral ballots cast for president and vice president and to open the certificates `` in the Presence of the Senate and House of Representatives , '' so that the total votes could be counted ) . Since the 1950s , vice presidents have presided over few Senate debates . Instead , they have usually presided only on ceremonial occasions , such as joint sessions , or at times to announce the result of significant legislation or nomination , or when a tie vote on an important issue is anticipated . </P>
when does the president of the senate vote
when does the president of the senate vote
in the case of a tie
in the case of a tie