State Apportionment and Redistricting Deadlines
- Historical Apportionment Data MapCreated and maintained by the US Census Bureau, this interactive data map allows a user to explore changes in congressional representation over time.
- State Redistricting DeadlinesA searchable list of redistricting deadlines for state legislatures and congressional districts from the National Conference of State Legislatures (NCSL).
- Who Draws the Lines?Includes downloadable data for the fifty states including who performs redistricting in each state, how many people make-up this body, and to which political parties have a controlling majority. Website maintained by Prof. Justin Levitt of Loyola Law School.
Books
CQ′s Encyclopedia of the U. S. Census by Call Number: HA37.U55 C66 2000ISBN: 1568024282Publication Date: 2000-07-10
Redistricting: a manual for analysts, practiioners, and citizens by ISBN: 9783030158279Publication Date: 2019
CQ Press Voting and Elections Collection Articles
- Reapportionment and Redistricting: Judicial Historya broad overview of supreme court rulings related to reapportionment and redistricting.
- One Person, One Votearticle describes the evolution of the understanding that redistricting can dilute voter rights.
More information on the Census
To learn more about the Decennial census, along with other data collecting activities of the US Census Bureau, visit Amherst College's LibGuide entitled "Find US Census Information" created by Dawn Cadogan.
Why is the Census so important?
The US Census is the basis by which seats in the House of Representatives are apportioned. The Apportionment Act of 1941 created the "the method of equal proportions" which distributes congressional seats by population (as established by the census) following the awarding of at least one seat per state. This process of reapportionment occurs after the decennial census, which happens every 10 years in years ending in "0". The census counts all residents of the United States, both citizens and non-citizens, but does not include residents outside of the states in apportionment calculations (such as those in the District of Columbia and Puerto Rico). Federal employees residing abroad are also counted. You can view the 2020 Census reapportionment data online. While the federally conducted census informs apportionment, there is no federal legislation outlining how House seats should be allocated within each state. Therefore, redistricting is governed largely by state laws and party politics with some federal oversight (due to historic repression of marginalized peoples' voting rights). COVID-19 delayed the census which has effected reapportionment and redistricting, as reported by Politico.
Federal law relating to apportionment:
- The Constitution:
- U.S. Const. art. 1, §4
- U.S. Const. art. 1, §2, cl. 3, amended by U.S. Const. amend. XIV §2
- Statutes & Legislation:
- 2 U.S.C. § 2a
- 3 U.S.C. § § 1-402
- Permanent Apportionment Act of 1929
- Apportionment Act of 1941
Redistricting Cases Heard at the Supreme Court
for general summaries of the following cases and more, click on the NCSL logo.
full cases linked below via WestLaw.
- Baker v. Carr (1962)"For the first time, the court held that the federal courts had jurisdiction to consider constitutional challenges to state legislative redistricting plans." from the NCSL
- Reynolds v. Sims (1964)" Both houses of a bicameral state legislature must be apportioned substantially according to population. Legislative districts may deviate from strict population equality only as necessary to give representation to political subdivisions and provide for compact districts of contiguous territory. Legislative districts should be redrawn to reflect population shifts at least every 10 years. Once a constitutional violation has been shown, a court should take equitable action to correct it, bearing in mind the practical requirements of running an election." from the NCSL
- Gaffney v. Cummings (1973)" The court upheld a legislative redistricting plan in which the total deviation was 1.81 percent for the Senate and 7.83 percent for the House. This indicates that legislative plans with a total deviation of 10% or less are presumptively constitutional although 10 percent is not a safe harbor." from the NCSL
- Evenwel v. Abbott, (2016)"Total population is a permissible metric for calculating compliance with “one person, one vote.” from the NCSL
- Shaw v. Reno (1993)" Legislative and congressional districts will be struck down by courts for violating the Equal Protection Clause if they cannot be explained on grounds other than race. While not dispositive, “bizarrely shaped” districts are strongly indicative of racial intent." from the NCSL
- Shelby County v. Holder (2013)"Section 5 of the Voting Rights Act no longer applies to any jurisdictions in the United States. As a result, redistricting plans and other changes in voting laws, such as voter identification requirements, need not be approved before they take effect." from the NCSL
Videos about the US Census, Contemporary Reapportionment and Redistricting
Reapportionment vs. Redistricting
"The census, apportionment, and redistricting are interrelated activities that affect representation in the U.S. House of Representatives. Congressional apportionment (or reapportionment) is the process of dividing seats for the House among the 50 states following the decennial census. Redistricting refers to the process that follows, in which states create new congressional districts or redraw existing district boundaries to adjust for population changes and/or changes in the number of House seats for the state. At times, Congress has passed or considered legislation addressing apportionment and redistricting processes under its broad authority to make law affecting House elections under Article I, Section 4, of the U.S. Constitution. These processes are all rooted in provisions in Article I, Section 2 (as amended by Section 2 of the Fourteenth Amendment)." Sarah J. Eckman, Apportionment and Redistricting Process for the U.S. House of Representatives, Congressional Research Service (2019).
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Congressional redistricting: legal and constitutional issues
"Congressional redistricting is the drawing of district boundaries from which the people choose their representatives to the U.S. House of Representatives. The legal framework for congressional redistricting resides at the intersection of the Constitution’s limits and powers, requirements prescribed under federal law, and the various processes imposed by the states. Prior to the 1960s, court challenges to redistricting plans were considered non-justiciable political questions that were most appropriately addressed by the political branches of government, not the judiciary. In 1962, in the landmark ruling of Baker v. Carr, the Supreme Court pivoted and held that a constitutional challenge to a redistricting plan was not a political question and was justiciable. Since then, a series of constitutional and legal challenges have significantly shaped how congressional districts are drawn." L. Paige Whitaker, Congressional Redistricting: Legal and Constitutional Issues, Congressional Research Service (2016).