Legislative branch of the United States federal government in the context of "56th United States Congress"

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.