Final answer:
The Vice President's constitutional duty is to preside over the Senate and cast tie-breaking votes, in addition to being prepared to assume the presidency if necessary.
Step-by-step explanation:
The constitutional duty of the Vice President is to preside over the Senate and cast the deciding vote in the event of a tie. The Vice President only has a chance to vote in the Senate if there is a “tie” on a proposed bill or nomination. This role is defined in the Constitution and has been the standard practice since the establishment of the United States. Outside of this duty, the influence and tasks of the Vice President have varied over time, with some Vice Presidents taking on more significant roles depending on the administration they serve under. Additionally, the Vice President is also tasked with assuming the presidency in the case that the President is unable to serve due to death, resignation, or incapacity.