President pro tempore of the United States Senate

President pro tempore of the United States Senate
Incumbent Orrin Hatch (R) since January 6, 2015
Style	Mr. President (Informal and within the Senate) The Honorable (Formal)
Appointer	Elected by the U.S. Senate
Term length	During the pleasure of the Senate and until another is elected or their term of office as a Senator expires
Constituting instrument	U.S. Constitution
Inaugural holder	John Langdon April 6, 1789
Formation	March 4, 1789
Succession	Third in the presidential line of succession
Deputy	Any senator, typically a member of the majority party, designated by the President pro tempore

The president pro tempore of the United States Senate (/ˌproʊ ˈtɛmpəriː/ or /ˌproʊ ˈtɛmpəreɪ/), also president pro tem, is the second-highest-ranking official of the United States Senate. Article One, Section Three of the United States Constitution provides that the Vice President of the United States is, despite not being a senator, the President of the Senate, and mandates that the Senate must choose a president pro tempore to act in the Vice President's absence. Unlike the vice president, the president pro tempore is an elected member of the Senate, able to speak or vote on any issue. Selected by the Senate at large, the president pro tempore has enjoyed many privileges and some limited powers. During the vice president's absence, the president pro tempore is empowered to preside over Senate sessions. In practice, neither the vice president nor the president pro tempore usually presides; instead, the duty of presiding officer is rotated among junior senators of the majority party to give them experience in parliamentary procedure.