section three provides that the vice president is the president of the senate. when serving in this capacity, the vice president, who is not a member of the senate, may cast a vote to break a tie. early in the nation's history, vice presidents frequently presided over the senate. in modern times, the vice president usually does so only during ceremonial occasions or when a tie in the voting is anticipated. a tie-breaking vote has been cast 243 times by 35 different vice presidents.