Answer: The Constitution gives the vice president the role of presiding over the Senate, and voting in the Senate if there is a tie. The vice president's only other formal responsibility is taking over the presidency if the president dies.
Explanation: The only duty the U.S. Constitution assigns the Vice President is to act as presiding officer of the Senate. But the Vice President also serves as ceremonial assistant to the President and is an important part of the President's administration.
The Truman Doctrine was established to aid nations that were fighting against communism. President Truman highly disagreed with communism, which is what lead him to creating the doctrine.
