A quorum call is a procedure used in both houses of Congress to bring to the floor the number of members who must be present for the legislative body to conduct its business.
The quorum call is established in Article I, Section V of the U.S. Constitution:
Each House shall be the Judge of the Elections, Returns and Qualifications of its own Members, and a Majority of each shall constitute a Quorum to do Business; but a smaller number may adjourn from day to day and may be authorized to compel the Attendance of absent Members, in such Manner, and under such Penalties as each House may provide.
Each chamber needs a majority of its members present in order to conduct business. A majority of the U.S. House constitutes at least 218 members, while 51 senators form a quorum in the U.S. Senate. Quorum rules are often applied to local and state legislatures due to their presence in the Constitution and Robert’s Rules of Order.
Quorum calls may be used for their original purpose (“live quorum calls”) or as a delaying tactic (“routine quorum calls”). A representative can trigger a roll call vote in the House using a point of order. The presiding officer takes a headcount and calls a recess if there isn’t a quorum. From 1796 to 1890, the House used the number of votes on each measure to determine if a quorum was present. Speaker Thomas Reed (R) led a change in the chamber’s rules to compel a headcount to avoid votes that fail to reach a quorum.
Senators can raise questions about the chamber’s quorum at any point to force a roll call by the clerk. The chamber may be recessed until a quorum is reached or the sergeant of arms sent to request the presence of a quorum. This tactic can be used to allow time for behind-the-scenes negotiations between the parties. A call can also delay a vote until certain legislators back in the chamber.
Roll Call (January 31, 2020): “Before the vote, the Senate broke for a quorum call after arguments from each side for and against hearing from witnesses.”
Politico (January 21, 2020): “The chamber went into a brief quorum call to see what the next step is, and when the proceeding restarted it was clear no deal was reached as the Senate proceeded into a debate as long as two hours over subpoenaing Defense Department documents.”
Vox (July 3, 2018): “First, they’d initiate a quorum call or a roll-call vote. This, of course, would require a Democrat to be in the chamber, and perhaps several other Democrats to support a request for a vote or a quorum call.”