Presiding Officer of the United States Senate in the context of "Vice President of the United States"

The vice president of the United States (VPOTUS, or informally, veep) is the second-highest ranking office in the executive branch of the U.S. federal government, after the president of the United States, and ranks first in the presidential line of succession. The vice president is also an officer in the legislative branch, as the president of the Senate. In this capacity, the vice president is empowered to preside over the United States Senate, but may not vote except to cast a tie-breaking vote. The vice president is elected at the same time as the president to a four-year term of office by the people of the United States through the Electoral College, but the electoral votes are cast separately for these two offices. Following the passage in 1967 of the Twenty-fifth Amendment to the US Constitution, a vacancy in the office of vice president may be filled by presidential nomination and confirmation by a majority vote in both houses of Congress. This was based on the Tyler Precedent set in 1841 when John Tyler became the first vice president to take over for a deceased president following the death of William Henry Harrison.

The modern vice presidency is a position of significant power and is widely seen as an integral part of a president's administration. The presidential candidate selects the candidate for the vice presidency as their running mate in the lead-up to the presidential election. While the exact nature of the role varies in each administration, since the vice president's service in office is by election, the president cannot dismiss the vice president, and the personal working-relationship with the president varies, most modern vice presidents serve as a key presidential advisor, governing partner, and representative of the president. The vice president is also a statutory member of the United States Cabinet and United States National Security Council and thus plays a significant role in executive government and national security matters. As the vice president's role within the executive branch has expanded, the legislative branch role has contracted; for example, vice presidents now preside over the Senate only infrequently.

The president pro tempore of the United States Senate (often shortened to president pro tem) is the second-highest-ranking official of the United States Senate, after the vice president. According to Article One, Section Three of the United States Constitution, the vice president of the United States is the president of the Senate (despite not being a senator), and the Senate must choose a president pro tempore to act in the vice president's absence.

The president pro tempore is elected by the Senate as a whole, usually by a resolution which is adopted by unanimous consent without a formal vote. The Constitution does not specify who can serve in this position, but the Senate has always elected one of its current members. Unlike the vice president, the president pro tempore cannot cast a tie-breaking vote when the Senate is evenly divided. The president pro tempore has enjoyed many privileges and some limited powers.

The positions of majority leader and minority leader are held by two United States senators and people of the party leadership of the United States Senate. They serve as chief spokespersons for their respective political parties, holding the majority and the minority in the chamber. They are each elected to their posts by the senators of their party caucuses: the Senate Democratic Caucus and the Senate Republican Conference.

By Senate precedent, the presiding officer gives the majority leader priority in obtaining recognition to speak on the floor. The majority leader serves as the chief representative of their party in the Senate and is considered the most powerful member of the chamber. They also serve as the chief representative of their party in the entire Congress if the House of Representatives, and thus the office of the speaker of the House, is controlled by the opposition party. The Senate's executive and legislative business is also managed and scheduled by the majority leader.