The Vice President of the United States, also simply known as a vice president, is a person elected by votes, as the running mate of the winning candidate for President of the United States, to be the second in the line of succession for the presidency of the United States of America. The vice president is also the President of the United States Senate, and as such can break a tie for anything voted on by the Senate.

The vice president and the president comprise the Executive Branch of the United States. The federal law enforcement agency attached to the Executive Branch is the United States Marshals Service, the oldest federal law enforcement agency in the United States. The office of the vice president is in the White House, which is located in Washington, D.C.

In 1955, after learning that the president in 1985 was Ronald Reagan, who was an actor in 1955, Emmett Brown sarcastically asked Marty McFly whether the vice president was Jerry Lewis.

As the second in the line of succession to the presidency of the United States, the vice president can become president when the president dies. This happened in 1923, when Calvin Coolidge, the 29th vice president, became the 30th president after Warren Harding died suddenly during a speaking tour. This happened again in 1963, when Lyndon B. Johnson, the 37th vice president, became the 36th president after the assassination of John F. Kennedy.

If the vice president resigns, the president can appoint a new vice president. This happened in 1973 when the 39th vice president, Spirow Agnew, resigned in 1973 and the 37th president (and formerly, the 36th vice president), Richard Nixon, appointed Gerald Ford as the 40th vice president. Likewise, the vice president can also ascend to the presidency when the president resigns. This happened in 1974, when Nixon himself resigned, and Gerald Ford became the 38th president.

In the altered 1985A timeline, Richard Nixon never resigned, and had been elected to his fifth term in 1983, with help from the rich and powerful Biff Tannen, and promised to end the war in Southeast Asia and the Vietnam War by 1985.

Sometimes, someone is elected president following a successful turn as vice president. This happened when George H. W. Bush, the 43rd vice president from 1981 to 1989, under president Ronald Reagan, was elected the 41st president in 1988.