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.