A small formal job, and a much larger practical one that depends entirely on the President.

The Constitution gives the Vice President exactly two clear formal roles: preside over the Senate, and succeed the President when required. Everything else — advising, policy leadership, foreign diplomacy, political strategy — is a modern practice that depends entirely on what a given President wants the role to be.

The Vice President of the United States shall be President of the Senate, but shall have no Vote, unless they be equally divided.

U.S. Constitution, Article I, Section 3

Formal roles2
Senate tie-breakingYes
Succession position1st in line
Modern dutiesVary by administration

What’s Actually in the Constitution

President of the Senate

Formally presides over the Senate, and can cast a tie-breaking vote when the chamber is evenly split — a real, occasionally decisive power.

First in succession

Constitutionally first in line to become President if the office becomes vacant.

What Modern Vice Presidents Actually Do

Everything beyond the two formal roles above is practice, not constitutional requirement — and it depends heavily on the individual President and administration.

Worth knowing

The Vice President’s real influence has nothing to do with formal constitutional power

A common misconception is that a Vice President’s importance can be measured by their constitutional authority. That authority is genuinely minimal — a tie-breaking Senate vote and a succession position. A Vice President’s actual influence comes entirely from informal trust and delegation from the President, which is why the office’s real significance has varied enormously from one administration to the next, even though the constitutional text hasn’t changed at all.