article: President pro tempore of the United States Senate
links: United States Republican Party Arizona List of United States Senators from Alaska Two-party system Richard Russell, Jr. Arthur Vandenberg Chuck Grassley Andrew Johnson Carl Hayden Robert Byrd Daniel Inouye Georgia (U.S. state) Hubert Humphrey David Rice Atchison South Carolina Hawaii Benjamin Wade Utah United States Constitution United States Ohio Michigan West Virginia United States Senate Strom Thurmond Republican Party (United States) Patrick Leahy Ted Stevens Orrin Hatch Iowa Missouri U.S. presidential line of succession Vice President of the United States US states Vermont United States presidential line of succession Patty Murray John Langdon