What is President pro tempore of the United States Senate?
{{Infobox political post |post = President Pro Tempore |body = <br />the United States Senate |insignia = President Pro Tempore US Senate Seal.svg |insigniasize = 150px |image = Chuck Grassley official photo 2017 (cropped).jpg |incumbent = [[Chuck Grassley]] |incumbentsince = January 3, 2025 |style = Mr./Mrs. President<br /><small>(Informal and within the Senate)</small><br />The Honorable<br /><small>(Formal)</small> |appointer = Elected by the [[United States Senate|U.S. Senate]] |formation = [[United States Constitution|U.S. Constitution]]<br />March 4, 1789 |succession = [[United States presidential line of succession|Third]] |inaugural = [[John Langdon]]<br />April 6, 1789 }} The '''president ''pro tempore''''' ({{IPAc-en|ˌ|p|r|oʊ|_|ˈ|t|ɛ|m|p|ər|iː}} or {{IPAc-en|ˌ|p|r|oʊ|_|ˈ|t|ɛ|m|p|ər|eɪ}}),<ref>{{cite web |url=http://research.lawyers.com/glossary/pro-tempore.html |title=Pro tempore Legal Definition |publisher=Lawyers.com}}</ref> or '''president pro tem''', '''of the United States Senate''' is the longest serving [[senator]] from the majority [[political party]] in the [[United States Senate]]. According to the [[United States Constitution|Constitution]], this is the fourth highest office in the [[United States]]. It is the third in the [[U.S. presidential line of succession]] (behind the [[Vice President of the United States|vice president]] and the [[speaker of the House]]). Many [[US states|state]] senates also use the office of President pro tem. Officially the vice president is the person in charge of the Senate, but they are not a Senator. [[Chuck Grassley]] ([[Republican Party (United States)|R]]-[[Iowa|IA]]) is the current president [[pro tempore]] {{as of|2025|01|03|df=US|lc=yes|since=y}}. When the vice president cannot be in charge, the president pro tempore is in charge of the Senate. Many people still think of the president pro tempore as ''[[de facto]]'' president of the Senate. [[Benjamin Wade]] was only one