On Wednesday, Speaker Nancy Pelosi announced that, while the coronavirus epidemic continues, Members of Congress and staff would be required to wear masks while present in the House Chamber (except for when a Member is recognized for debate).

Why does Speaker Nancy Pelosi think she can require Members of Congress to wear masks while in the Chamber of the House?

She can do it because Members of the House voted to give her that discretion.

At the beginning of each Congress, the House adopts its rules. Since 1789, the House has continually adopted the following rule, in some form or another:

The Speaker shall preserve order and decorum and, in case of disturbance or disorderly conduct in the galleries or in the lobby, may cause the same to be cleared. (Rule I, clause 2)

Proper attire for Members of Congress is considered an aspect of decorum, and the Speaker is authorized to regulate attire for Members in the Chamber.  House Rule 2, clause 3(a) requires the Sergeant-at-Arms, the House’s chief security official, to “maintain order under the direction of the Speaker or other presiding officer.” According to the Precedents of the House, the Speaker (or Speaker pro tempore), but not another Member of Congress, may not call upon the Sergeant-at-Arms to enforce the rules of decorum.

When Speaker Pelosi announced the masking requirement, she noted that Members and staff who are not wearing masks would not be permitted to enter the Chamber.  By no means would this be the first time a Member is excluded for failing to follow rules concerning proper attire. For instance, in July 1979, the thermostat in the House Chamber was set to 78 degrees to comply with an Executive order concerning energy conservation. Naturally, the Chamber heated up. When a Member presented himself in the House in less than business attire, Speaker Tip O’Neill ordered him to depart until he was properly clothed. Later that day, a Member offered a resolution relaxing the dress code, but the House tabled it by a lopsided vote of 303 to 105. Immediately after that, the House considered another resolution saying “Members should be required to wear proper attire as determined by the Speaker and may not be admitted to the Hall of the House of Representatives unless in compliance with the Speaker’s announcement” (H.Res. 370, 95th Congress). The House agreed to it by voice vote.

Normally, business attire is considered proper for attending House proceedings. Rule XVII, clause 5, explicitly forbids head wear, except those coverings worn for religious reasons. The prohibition of headwear is a long-standing rule, but the exception for religious reasons was added to the rules at the beginning of this Congress. Members can now add face masks to proper attire or sit out the debates in the House.

When Speaker Pelosi made her announcement, she stated that Members and staff are required to wear masks “at all times in the Hall of the House.” “Hall of the House” is not synonymous with the House Floor or House Chamber. According to the Precedents of the House, the term includes “the House Chamber and its galleries, as well as cloakrooms for each party organization.” Any C-Span viewer is familiar with the House Chamber, and visitors to D.C. often get the chance to watch proceedings from the House galleries. Far fewer are familiar with the Cloakrooms.  These are long rooms connected to the Chamber for Members to gather in a less formal setting. Each party has its own cloakroom. They are a sort of all-purpose room for Members to relax, socialize and also engage in legislative work like negotiating with colleagues or talking over strategies. (Private as they are, few non-Members ever see them. The House Historian’s website, however, has a great look at how they’ve evolved over the years: “Cloaked In Secrecy.”)

Finally, Speaker Pelosi announced that the masking requirement would be in place “during the pendency of a ‘covered period,’ pursuant to House Resolution 965.” On May 15 of this year, the House adopted Resolution 965 to permit proxy voting on the Floor and remote committee proceedings during the coronavirus pandemic. The resolution allows the Speaker to designate a “covered period” in which Members may vote by proxy vote and committees may meet remotely after the Sergeant-at-Arms notifies her that there is a public health emergency due to the coronavirus epidemic. So unlike general rules about attire which are in force at all times, Speaker Pelosi’s regulation about masking will be in effect whenever she announces a “covered period” for the purpose of House Resolution 965.

Mark Strand is the President of the Congressional Institute and Timothy Lang is a research director. The Sausage Factory blog is a Congressional Institute project dedicated to explaining parliamentary procedure, Congressional politics, and other issues pertaining to the Legislative Branch.