United States Senate

===Presiding officer===
{{main|Presiding Officer of the United States Senate}}
Under the Constitution, the [[Vice President of the United States|vice president]] serves as president of the Senate. They may vote in the Senate (''[[ex officio]]'', for they are not an elected member of the Senate) in the case of a tie, but are not required to.<ref>{{Cite web |title=Glossary Term: vice president |url=https://www.senate.gov/reference/glossary_term/vice_president.htm |url-status=dead |archive-url=https://web.archive.org/web/20161130151742/http://www.senate.gov/reference/glossary_term/vice_president.htm |archive-date=November 30, 2016 |access-date=November 10, 2016 |publisher=United States Senate}}</ref> 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 swearing in new senators, 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.

The Constitution authorizes the Senate to elect a [[President pro tempore of the United States Senate|president pro tempore]] ([[Latin]] for "president for a time"), who presides over the chamber in the vice president's absence and is, by custom, the senator of the majority party with the longest record of continuous service.<ref>{{Cite web |title=Glossary Term: president pro tempore |url=https://www.senate.gov/reference/glossary_term/president_pro_tempore.htm |archive-url=https://web.archive.org/web/20161205151015/http://www.senate.gov/reference/glossary_term/president_pro_tempore.htm |archive-date=December 5, 2016 |access-date=November 10, 2016 |publisher=United States Senate}}</ref> Like the vice president, the president pro tempore does not normally preside over the Senate, but typically delegates the responsibility of presiding to a majority-party senator who presides over the Senate, usually in blocks of one hour on a rotating basis. Frequently, freshmen senators (newly elected members) are asked to preside so that they may become accustomed to the rules and procedures of the body. It is said that, "in practice they are usually mere mouthpieces for [[Parliamentarian of the United States Senate|the Senate's parliamentarian]], who whispers what they should do".<ref>{{Cite news |last=Mershon |first=Erin |date=August 2011 |title=Presiding Loses Its Prestige in Senate |work=Roll Call |url=http://www.rollcall.com/news/presiding-loses-its-prestige-in-senate-207942-1.html |url-status=dead |access-date=February 8, 2017 |archive-url=https://web.archive.org/web/20170208194601/http://www.rollcall.com/news/presiding-loses-its-prestige-in-senate-207942-1.html |archive-date=February 8, 2017}}</ref>

The [[Presiding Officer of the United States Senate|presiding officer]] sits in a chair in the front of the Senate chamber. The powers of the presiding officer of the Senate are far less extensive than those of the [[Speaker of the United States House of Representatives|speaker of the House]]. The presiding officer calls on senators to speak (by the rules of the Senate, the first senator who rises is recognized); ruling on [[points of order]] (objections by senators that a rule has been breached, subject to appeal to the whole chamber); and announcing the results of votes.