Leahy 3rd in Line to Presidency He is now president pro tempore of the Senate By John Johnson, Newser Staff Posted Dec 18, 2012 3:27 PM CST 17 comments Comments Vice President Joe Biden, right, reenacts the swearing in of Sen. Patrick Leahy, D-Vt., as president pro tempore of the Senate in the Old Senate Chamber on Capitol Hill. (AP Photo/Susan Walsh) (Newser) – The death of Daniel Inouye of Hawaii yesterday has Democrats shuffling committee posts and such, but one change in particular carries some import with the Constitution. Patrick Leahy of Vermont got sworn in as president pro tempore of the Senate, which puts him third in line to the presidency behind Joe Biden and John Boehner, reports the Hill. Inouye's death makes Leahy, who took office in 1975, the longest-serving senator in the chamber, notes Politico. For the record, Hillary Clinton is next in line behind Leahy.