As the longest-serving Democratic senator, Byrd served as President pro tempore four times when his party was in the majority: from 1989 until the Republicans won control of the Senate in 1995; for 17 days in early 2001, when the Senate was evenly split between parties and outgoing Vice President Al Gore broke the tie in favor of the Democrats; when the Democrats regained the majority in June 2001 after Senator Jim Jeffords of Vermont left the Republican Party to become an independent; and again from 2007 to his death in 2010, as a result of the 2006 Senate elections. In this capacity, Byrd was third in the line of presidential succession at the time of his death, behind Vice President Joe Biden and House Speaker Nancy Pelosi.