The census, apportionment, and congressional redistricting are interrelated processes that occur every decade. The U.S. Constitution provides that a decennial census determines the distribution of U.S. House seats across states, though the federal government today also uses census data for other purposes, such as distributing funding to states and localities. The process of dividing House seats to states is known as apportionment (or reapportionment). Each state must receive at least one House seat, and additional seats are distributed proportionally based on state population size. States then engage in redistricting, creating or redrawing geographic subdivisions for each House district, with relatively equal-sized populations.
Timelines for the census and apportionment are provided in federal statute and generally occur as scheduled every decade. The COVID-19 pandemic, however, is affecting 2020 census field operations, and this could have consequences for the apportionment and redistricting processes that follow the completion of the census. This Insight provides background on the typical timing of the census, apportionment, and redistricting, as well as a brief discussion of recent census-related changes and proposals that may affect apportionment and redistricting following the 2020 census.
Figure 1 provides a visual timeline of the typical census, apportionment, and redistricting processes further described in this section. Federal statute requires that April 1 of any year ending in "0" marks the official decennial census date, although the Census Bureau begins certain population counts and outreach prior to April 1. A count known as the apportionment population, which reflects the total resident population in each state, is used to distribute House seats. The apportionment population includes minors and noncitizens, in addition to Armed Forces and federal civilian personnel and their dependents living abroad. Within nine months of the decennial census date (December 31 of the year ending in "0"), the Secretary of Commerce reports the apportionment population to the President. The Census Bureau has, in past years, released apportionment counts publicly at about the same time they are officially presented to the President.
Within the first week of the first regular session of the next Congress (typically, early January of a year ending in "1"), the President transmits a statement to Congress that provides information on how to apportion House seats. The President's message to Congress contains the number of people in each state (as determined by the decennial census and certain administrative records) and the resulting number of Representatives each state is entitled to, based on the total number of House Members (435) and using the method of equal proportions.
The Clerk of the House sends each state governor a certificate indicating the number of Representatives for each state within 15 calendar days of receiving the President's apportionment message. Each state receives the number of Representatives noted in the President's statement for its House delegation, beginning at the start of the next session of Congress (typically, early January of a year ending in "3"). States may then engage in their own redistricting processes before the start of the next Congress, and the timing of these processes varies based on state laws.
Source: CRS compilation, based on information from the U.S. Constitution, U.S. Code, U.S. Census Bureau, and state laws. Graphic created by Amber Hope Wilhelm, CRS Visual Information Specialist.
If the timeline for the census changes, the timeline for apportionment and redistricting processes may also be affected. As discussed, the apportionment timeline is generally set through federal law, and redistricting timelines vary by state and are generally set through state law.
Census operations for 2020 were underway as the COVID-19 pandemic was declared on March 11. Many Americans have completed the 2020 census, which was available online for the first time this year. Responses can also be made by phone or by mail. The Census Bureau provides in-person data collection for certain communities in remote areas and also conducts follow-up with nonrespondents. These field operations are not currently feasible due to public health concerns.
Two modifications to 2020 census field operations have been announced to date. On March 18, the Census Bureau temporarily suspended field operations through April 1. Further changes were announced on April 13, including the closure of field offices through June 1, 2020, and a revised schedule that would include the following proposed timeline:
The deadlines for the President to deliver apportionment counts and for the Census Bureau to deliver redistricting data to states are set by statute, and the Census Bureau has indicated that it is seeking statutory relief from Congress. On an April 13 call with some Members of Congress, Secretary of Commerce Wilbur Ross reportedly did not rule out the possibility of further census delays, depending on public health guidance. The House Committee on Oversight and Reform held a briefing on census-related issues later that week.
Four former Census Bureau directors have announced support for the extension of field operations. Proponents indicate that these adjustments are necessary to provide an accurate and complete census count while protecting the health of respondents and census workers. By shifting the census and apportionment timeline by several months, however, there are also concerns about subsequent effects on redistricting. For example, following the 2010 census, many states had begun (and some had completed) their redistricting processes by July 2011, but under this proposal, states might not receive their redistricting data until July 31, 2021. States with constitutional or statutory redistricting deadlines, and especially those with part-time legislatures or 2021 elections, might face particular challenges.