What is the President Pro Tempore?

The President Pro Tempore of the Senate is the senator who presides over the chamber when the Vice President is absent, which is most of the time. The position is established by Article I, Section 3 of the Constitution. The Latin phrase pro tempore means for the time being, reflecting that the role was originally meant to be temporary, filled only when the Vice President was unavailable.

In modern practice, the position has become continuous and ceremonial. By Senate tradition since the late 19th century, the President Pro Tempore is the longest-serving senator from the majority party. The current holder is generally a senior figure with decades of experience in the chamber. Recent President Pro Tempores have included Robert Byrd of West Virginia, Daniel Inouye of Hawaii, Patrick Leahy of Vermont, and Patty Murray of Washington.

The President Pro Tempore presides over the Senate when neither the Vice President nor a designated junior senator is in the chair, but in practice rarely sits in the presiding chair for long stretches. Most routine floor proceedings are run by junior senators rotating through the chair to gain procedural experience.

The President Pro Tempore signs legislation and other official documents on behalf of the Senate, can administer oaths, and chairs joint sessions of Congress in the Vice President's absence. The position is third in the line of presidential succession under the Presidential Succession Act of 1947, after the Vice President and the Speaker of the House. The succession rule means that in extraordinary circumstances, a President Pro Tempore could become President of the United States, though this has never happened.

The role has changed significantly since the early Republic, when the Senate often elected a President Pro Tempore for a single day or session. The modern continuous tenure dates from 1890 and reflects the institutional development of party leadership in the Senate. Real day-to-day Senate leadership rests with the Senate Majority Leader and the Senate Minority Leader, who control the floor schedule and party strategy.