Attendance
The Constitution specifies that a majority of members
constitutes a quorum to do business in each house.
Representatives and senators rarely force the presence of a
quorum by demanding quorum calls; thus, in most cases, debates
continue even if a majority is not present.
The Senate uses roll-call votes; a clerk calls out the names of
all the senators, each senator stating "aye" or "no" when his or
her name is announced. The House reserves roll-call votes for
the most formal matters, as a roll-call of all 435
representatives takes quite some time; normally, members vote by
electronic device. In the case of a tie, the motion in question
fails. In the Senate, the Vice President may (if present) cast
the tiebreaking vote.