The Vice President of the United States is given only one duty in the Constitution: to preside over the Senate. However, in practice, he seldom shows up to do this since this job is primarily a formality and doesn’t give him any real power, except to break tie votes.

The vice president can be expected to be in the Senate chamber only when

Explanation

The passage states the one real power of the vice president is to break tie votes, so he or she can be expected to be present when a Senate vote is scheduled that will be very close. Otherwise, serving as presiding officer is a formality that doesn’t even allow the vice president to make speeches, or take part in a debate. Presiding over an impeachment trial, would be largely a formality too; however, the Constitution actually gives this duty to the Chief Justice of the Supreme Court so there is no conflict of interest (the vice president would become president if the president were impeached).