It is desirable that Congress should have the _final_ authority in
providing for the election of its own members, because the very
existence of the Union might otherwise be left, at times, to the whims
of the State legislatures.

President of the Senate.--Section 3, Clause 4. _The Vice-President
of the United States shall be President of the Senate, but shall have no
vote unless they be equally divided_.

Other Officers.--Section 3, Clause 5. _The Senate shall choose
their other officers, and also a President pro tempore, in the absence
of the Vice-President, or when he shall exercise the office of President
of the United States_.

The Vice-President of the United States is the presiding officer of the
Senate. He cannot take part in debates, and has no vote unless there be
a tie. In marked contrast with the power of the speaker, he cannot name
the committees, and has no direct authority in legislation. Indeed, the
office is regarded as one of so little influence that it is sometimes
difficult to secure, as candidates for it, men of recognized prominence.

The other officers of the Senate are secretary, chief clerk,
sergeant-at-arms, chaplain, postmaster, librarian, and doorkeeper, none
of whom is a member of the Senate. It is desirable, in the absence of
the Vice-President, that the Senate should have a presiding officer. At
the opening of the session, therefore, that body chooses from its own
members a president _pro tempore_. He may vote on any question, but
cannot cast the deciding vote in case of a tie.