Redistricting is the process of enacting new district boundaries for elected offices, particularly for offices in the U.S. House of Representatives and state legislatures. All United States Representatives and state legislators are elected from political divisions called districts. District lines are redrawn every 10 years following completion of the United States census. The federal government stipulates that districts must have nearly equal populations and must not discriminate on the basis of race or ethnicity.[1]
The states themselves determine their own redistricting methods. These methods vary from state to state and, sometimes, within a state (for example, different methods may apply to congressional redistricting than to state legislative redistricting). This article details redistricting methods by state for both congressional and state legislative redistricting.[1]
This section includes background information on federal requirements for congressional redistricting, state legislative redistricting, state-based requirements, redistricting methods used in the 50 states, gerrymandering, and recent court decisions.
According to Article I, Section 4 of the United States Constitution, the states and their legislatures have primary authority in determining the "times, places, and manner" of congressional elections. Congress may also pass laws regulating congressional elections.[2][3]
“ | The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing Senators.[4] | ” |
—United States Constitution |
Article I, Section 2 of the United States Constitution stipulates that congressional representatives be apportioned to the states on the basis of population. There are 435 seats in the United States House of Representatives. Each state is allotted a portion of these seats based on the size of its population relative to the other states. Consequently, a state may gain seats in the House if its population grows or lose seats if its population decreases, relative to populations in other states. In 1964, the United States Supreme Court ruled in Wesberry v. Sanders that the populations of House districts must be equal "as nearly as practicable."[5][6][7]
The equal population requirement for congressional districts is strict. According to All About Redistricting, "Any district with more or fewer people than the average (also known as the 'ideal' population), must be specifically justified by a consistent state policy. And even consistent policies that cause a 1 percent spread from largest to smallest district will likely be unconstitutional."[7]
The United States Constitution is silent on the issue of state legislative redistricting. In the mid-1960s, the United States Supreme Court issued a series of rulings in an effort to clarify standards for state legislative redistricting. In Reynolds v. Sims, the court ruled that "the Equal Protection Clause [of the United States Constitution] demands no less than substantially equal state legislative representation for all citizens, of all places as well as of all races." According to All About Redistricting, "it has become accepted that a [redistricting] plan will be constitutionally suspect if the largest and smallest districts [within a state or jurisdiction] are more than 10 percent apart."[7]
In addition to the federal criteria noted above, individual states may impose additional requirements on redistricting. Common state-level redistricting criteria are listed below.
In general, a state's redistricting authority can be classified as one of the following:[9]
The term gerrymandering refers to the practice of drawing electoral district lines to favor one political party, individual, or constituency over another. When used in a rhetorical manner by opponents of a particular district map, the term has a negative connotation but does not necessarily address the legality of a challenged map. The term can also be used in legal documents; in this context, the term describes redistricting practices that violate federal or state laws.[1][10]
For additional background information about gerrymandering, click "[Show more]" below.
The phrase racial gerrymandering refers to the practice of drawing electoral district lines to dilute the voting power of racial minority groups. Federal law prohibits racial gerrymandering and establishes that, to combat this practice and to ensure compliance with the Voting Rights Act, states and jurisdictions can create majority-minority electoral districts. A majority-minority district is one in which a racial group or groups comprise a majority of the district's populations. Racial gerrymandering and majority-minority districts are discussed in greater detail in this article.[11]
The phrase partisan gerrymandering refers to the practice of drawing electoral district maps with the intention of favoring one political party over another. In contrast with racial gerrymandering, on which the Supreme Court of the United States has issued rulings in the past affirming that such practices violate federal law, the high court had not, as of November 2017, issued a ruling establishing clear precedent on the question of partisan gerrymandering. Although the court has granted in past cases that partisan gerrymandering can violate the United States Constitution, it has never adopted a standard for identifying or measuring partisan gerrymanders. Partisan gerrymandering is described in greater detail in this article.[12][13]The Supreme Court of the United States has, in recent years, issued several decisions dealing with redistricting policy, including rulings relating to the consideration of race in drawing district maps, the use of total population tallies in apportionment, and the constitutionality of independent redistricting commissions. The rulings in these cases, which originated in a variety of states, impact redistricting processes across the nation.
For additional background information about these cases, click "[Show more]" below.
Alexander v. South Carolina State Conference of the NAACP — This case concerns a challenge to the congressional redistricting plan that the South Carolina legislature enacted after the 2020 census. In January 2023, a federal three-judge panel ruled that the state's 1st Congressional District was unconstitutional and enjoined the state from conducting future elections using its district boundaries. The panel's opinion said, "The Court finds that race was the predominant factor motivating the General Assembly’s adoption of Congressional District No. 1...Defendants have made no showing that they had a compelling state interest in the use of race in the design of Congressional District No. 1 and thus cannot survive a strict scrutiny review."[14] Thomas Alexander (R)—in his capacity as South Carolina State Senate president—appealed the federal court's ruling, arguing: :In striking down an isolated portion of South Carolina Congressional District 1 as a racial gerrymander, the panel never even mentioned the presumption of the General Assembly’s “good faith.”...The result is a thinly reasoned order that presumes bad faith, erroneously equates the purported racial effect of a single line in Charleston County with racial predominance across District 1, and is riddled with “legal mistake[s]” that improperly relieved Plaintiffs of their “demanding” burden to prove that race was the “predominant consideration” in District 1.[15] The U.S. Supreme Court scheduled oral argument on this case for October 11, 2023.[16]
At issue in Moore v. Harper, was whether state legislatures alone are empowered by the Constitution to regulate federal elections without oversight from state courts, which is known as the independent state legislature doctrine. On November 4, 2021, the North Carolina General Assembly adopted a new congressional voting map based on 2020 Census data. The legislature, at that time, was controlled by the Republican Party. In the case Harper v. Hall (2022), a group of Democratic Party-affiliated voters and nonprofit organizations challenged the map in state court, alleging that the new map was a partisan gerrymander that violated the state constitution.[17] On February 14, 2022, the North Carolina Supreme Court ruled that the state could not use the map in the 2022 elections and remanded the case to the trial court for further proceedings. The trial court adopted a new congressional map drawn by three court-appointed experts. The United States Supreme Court affirmed the North Carolina Supreme Court's original decision in Moore v. Harper that the state's congressional district map violated state law. In a 6-3 decision, Chief Justice John Roberts wrote that the "Elections Clause does not vest exclusive and independent authority in state legislatures to set the rules regarding federal elections.[18]
At issue in Merrill v. Milligan, was the constitutionality of Alabama's 2021 redistricting plan and whether it violated Section 2 of the Voting Rights Act. A group of Alabama voters and organizations sued Secretary of State John Merrill (R) and the House and Senate redistricting chairmen, Rep. Chris Pringle (R) and Sen. Jim McClendon (R). Plaintiffs alleged the congressional map enacted on Nov. 4, 2021, by Gov. Kay Ivey (R) unfairly distributed Black voters. The plaintiffs asked the lower court to invalidate the enacted congressional map and order a new map with instructions to include a second majority-Black district. The court ruled 5-4, affirming the lower court opinion that the plaintiffs showed a reasonable likelihood of success concerning their claim that Alabama's redistricting map violated Section 2 of the Voting Rights Act.[19]
In Gill v. Whitford, decided on June 18, 2018, the Supreme Court of the United States ruled that the plaintiffs—12 Wisconsin Democrats who alleged that Wisconsin's state legislative district plan had been subject to an unconstitutional gerrymander in violation of the First and Fourteenth Amendments—had failed to demonstrate standing under Article III of the United States Constitution to bring a complaint. The court's opinion, penned by Chief Justice John Roberts, did not address the broader question of whether partisan gerrymandering claims are justiciable and remanded the case to the district court for further proceedings. Roberts was joined in the majority opinion by Associate Justices Anthony Kennedy, Ruth Bader Ginsburg, Stephen Breyer, Samuel Alito, Sonia Sotomayor, and Elena Kagan. Kagan penned a concurring opinion joined by Ginsburg, Breyer, and Sotomayor. Associate Justice Clarence Thomas penned an opinion that concurred in part with the majority opinion and in the judgment, joined by Associate Justice Neil Gorsuch.[20]
In Cooper v. Harris, decided on May 22, 2017, the Supreme Court of the United States affirmed the judgment of the United States District Court for the Middle District of North Carolina, finding that two of North Carolina's congressional districts, the boundaries of which had been set following the 2010 United States Census, had been subject to an illegal racial gerrymander in violation of Section 2 of the Voting Rights Act. Justice Elena Kagan delivered the court's majority opinion, which was joined by Justices Clarence Thomas, Ruth Bader Ginsburg, Stephen Breyer, and Sonia Sotomayor (Thomas also filed a separate concurring opinion). In the court's majority opinion, Kagan described the two-part analysis utilized by the high court when plaintiffs allege racial gerrymandering as follows: "First, the plaintiff must prove that 'race was the predominant factor motivating the legislature's decision to place a significant number of voters within or without a particular district.' ... Second, if racial considerations predominated over others, the design of the district must withstand strict scrutiny. The burden shifts to the State to prove that its race-based sorting of voters serves a 'compelling interest' and is 'narrowly tailored' to that end." In regard to the first part of the aforementioned analysis, Kagan went on to note that "a plaintiff succeeds at this stage even if the evidence reveals that a legislature elevated race to the predominant criterion in order to advance other goals, including political ones." Justice Samuel Alito delivered an opinion that concurred in part and dissented in part with the majority opinion. This opinion was joined by Chief Justice John Roberts and Justice Anthony Kennedy.[21][22][23]
Evenwel v. Abbott was a case decided by the Supreme Court of the United States in 2016. At issue was the constitutionality of state legislative districts in Texas. The plaintiffs, Sue Evenwel and Edward Pfenninger, argued that district populations ought to take into account only the number of registered or eligible voters residing within those districts as opposed to total population counts, which are generally used for redistricting purposes. Total population tallies include non-voting residents, such as immigrants residing in the country without legal permission, prisoners, and children. The plaintiffs alleged that this tabulation method dilutes the voting power of citizens residing in districts that are home to smaller concentrations of non-voting residents. The court ruled 8-0 on April 4, 2016, that a state or locality can use total population counts for redistricting purposes. The majority opinion was penned by Justice Ruth Bader Ginsburg.[24][25][26][27]
Harris v. Arizona Independent Redistricting Commission was a case decided by the Supreme Court of the United States in 2016. At issue was the constitutionality of state legislative districts that were created by the commission in 2012. The plaintiffs, a group of Republican voters, alleged that "the commission diluted or inflated the votes of almost two million Arizona citizens when the commission intentionally and systematically overpopulated 16 Republican districts while under-populating 11 Democrat districts." This, the plaintiffs argued, constituted a partisan gerrymander. The plaintiffs claimed that the commission placed a disproportionately large number of non-minority voters in districts dominated by Republicans; meanwhile, the commission allegedly placed many minority voters in smaller districts that tended to vote Democratic. As a result, the plaintiffs argued, more voters overall were placed in districts favoring Republicans than in those favoring Democrats, thereby diluting the votes of citizens in the Republican-dominated districts. The defendants countered that the population deviations resulted from legally defensible efforts to comply with the Voting Rights Act and obtain approval from the United States Department of Justice. At the time of redistricting, certain states were required to obtain preclearance from the U.S. Department of Justice before adopting redistricting plans or making other changes to their election laws—a requirement struck down by the United States Supreme Court in Shelby County v. Holder (2013). On April 20, 2016, the court ruled unanimously that the plaintiffs had failed to prove that a partisan gerrymander had taken place. Instead, the court found that the commission had acted in good faith to comply with the Voting Rights Act. The court's majority opinion was penned by Justice Stephen Breyer.[28][29][30]
Most states are required to draw new congressional district lines every 10 years following completion of United States Census (those states comprising one congressional district are not required to redistrict). In 33 of these states, state legislatures play the dominant role in congressional redistricting. In nine states, commissions draw congressional district lines. In two states, hybrid systems are used, in which the legislatures share redistricting authority with commissions. The remaining states comprise one congressional district each, rendering redistricting unnecessary. See the map and table below for further details.[35][36]
In the table below, click on a state name for details about that state's redistricting procedures.
Congressional redistricting procedures | ||||
---|---|---|---|---|
State | Who draws the lines? | Details | Notes | |
Alabama | Legislature-dominant | Subject to veto | ||
Alaska | N/A | N/A | Alaska encompasses only one congressional district. | |
Arizona | Commission | Non-politician commission | ||
Arkansas | Legislature-dominant | Subject to veto | ||
California | Commission | Non-politician commission | ||
Colorado | Commission | Non-politician commission | ||
Connecticut | Legislature-dominant | Not subject to veto | ||
Delaware | N/A | N/A | Delaware encompasses only one congressional district. | |
Florida | Legislature-dominant | Subject to veto | ||
Georgia | Legislature-dominant | Subject to veto | ||
Hawaii | Commission | Non-politician commission | ||
Idaho | Commission | Non-politician commission | ||
Illinois | Legislature-dominant | Subject to veto | ||
Indiana | Legislature-dominant | Subject to veto | ||
Iowa | Legislature-dominant | Subject to veto; advisory commission | ||
Kansas | Legislature-dominant | Subject to veto | ||
Kentucky | Legislature-dominant | Subject to veto | ||
Louisiana | Legislature-dominant | Subject to veto | ||
Maine | Legislature-dominant | Subject to veto; advisory commission | ||
Maryland | Legislature-dominant | Subject to veto; advisory commission | ||
Massachusetts | Legislature-dominant | Subject to veto | ||
Michigan | Commission | Non-politician commission | ||
Minnesota | Legislature-dominant | Subject to veto | ||
Mississippi | Legislature-dominant | Subject to veto; advisory commission | ||
Missouri | Legislature-dominant | Subject to veto | ||
Montana | Commission | Non-politician commission | ||
Nebraska | Legislature-dominant | Subject to veto | ||
Nevada | Legislature-dominant | Subject to veto | ||
New Hampshire | Legislature-dominant | Subject to veto | ||
New Jersey | Commission | Politician commission | ||
New Mexico | Legislature-dominant | Subject to veto; advisory commission | ||
New York | Hybrid | N/A | A non-politician commission drafts maps. The legislature must reject two separate sets of commission-proposed plans before it can amend the commission's proposals. The legislature's amendments cannot modify the commission's proposal by more than 2% of any district's population. | |
North Carolina | Legislature-dominant | Not subject to veto | ||
North Dakota | N/A | N/A | North Dakota encompasses only one congressional district. | |
Ohio | Legislature-dominant | Subject to veto; advisory commission | ||
Oklahoma | Legislature-dominant | Subject to veto | ||
Oregon | Legislature-dominant | Subject to veto | ||
Pennsylvania | Legislature-dominant | Subject to veto | ||
Rhode Island | Legislature-dominant | Subject to veto; advisory commission | ||
South Carolina | Legislature-dominant | Subject to veto | ||
South Dakota | N/A | N/A | South Dakota encompasses only one congressional district. | |
Tennessee | Legislature-dominant | Subject to veto | ||
Texas | Legislature-dominant | Subject to veto | ||
Utah | Legislature-dominant | Subject to veto; advisory commission | ||
Vermont | N/A | N/A | Vermont encompasses only one congressional district. | |
Virginia | Hybrid | N/A | A commission divided evenly between politicians and non-politicians drafts maps. The General Assembly must vote to approve the maps without amending them. If the General Assembly rejects the first set of draft maps, the commission must submit another. If the General Assembly rejects this second set of draft maps, the Virginia Supreme Court is tasked with enacting new maps. | |
Washington | Commission | Non-politician commission | ||
West Virginia | Legislature-dominant | Subject to veto | ||
Wisconsin | Legislature-dominant | Subject to veto; advisory commission | ||
Wyoming | N/A | N/A | Wyoming encompasses only one congressional district. | |
Sources: All About Redistricting, "National Summary," accessed July 29, 2024, The American Redistricting Project, "State," accessed July 29, 2024 |
In 34 of the 50 states, state legislatures play the dominant role in state legislative redistricting. Commissions draw state legislative district lines in 14 states. In two states, hybrid systems are used, in which state legislature share redistricting authority with commissions. See the map and table below for further details.[35][36][37]
In the table below, click on a state name for details about that state's redistricting procedures.
State legislative redistricting procedures | ||||
---|---|---|---|---|
State | Who draws the lines? | Details | Notes | |
Alabama | Legislature-dominant | Subject to veto | ||
Alaska | Commission | Non-politician commission | ||
Arizona | Commission | Non-politician commission | ||
Arkansas | Commission | Politician commission | ||
California | Commission | Non-politician commission | ||
Colorado | Commission | Non-politician commission | ||
Connecticut | Legislature-dominant | Not subject to veto | ||
Delaware | Legislature-dominant | Subject to veto | ||
Florida | Legislature-dominant | Not subject to veto | ||
Georgia | Legislature-dominant | Subject to veto | ||
Hawaii | Commission | Non-politician commission | ||
Idaho | Commission | Non-politician commission | ||
Illinois | Legislature-dominant | Subject to veto | ||
Indiana | Legislature-dominant | Subject to veto | ||
Iowa | Legislature-dominant | Subject to veto; advisory commission | ||
Kansas | Legislature-dominant | Subject to veto | The state legislature drafts state legislative district maps, which are subject to gubernatorial veto. The Kansas Supreme Court must approve of the maps before they can be enacted. | |
Kentucky | Legislature-dominant | Subject to veto | ||
Louisiana | Legislature-dominant | Subject to veto | ||
Maine | Legislature-dominant | Subject to veto; advisory commission | ||
Maryland | Legislature-dominant | Not subject to veto; advisory commission | ||
Massachusetts | Legislature-dominant | Subject to veto | ||
Michigan | Commission | Non-politician commission | ||
Minnesota | Legislature-dominant | Subject to veto | ||
Mississippi | Legislature-dominant | Not subject to veto; advisory commission | ||
Missouri | Commission | Politician commission | ||
Montana | Commission | Non-politician commission | ||
Nebraska | Legislature-dominant | Subject to veto | ||
Nevada | Legislature-dominant | Subject to veto | ||
New Hampshire | Legislature-dominant | Subject to veto | ||
New Jersey | Commission | Politician commission | ||
New Mexico | Legislature-dominant | Subject to veto; advisory commission | ||
New York | Hybrid | N/A | A non-politician commission drafts maps. The legislature must reject two separate sets of commission-proposed plans before it can amend the commission's proposals. The legislature's amendments cannot modify the commission's proposal by more than 2% of any district's population. | |
North Carolina | Legislature-dominant | Not subject to veto | ||
North Dakota | Legislature-dominant | Subject to veto | ||
Ohio | Commission | Politician commission | ||
Oklahoma | Legislature-dominant | Subject to veto | ||
Oregon | Legislature-dominant | Subject to veto | ||
Pennsylvania | Commission | Politician commission | ||
Rhode Island | Legislature-dominant | Subject to veto; advisory commission | ||
South Carolina | Legislature-dominant | Subject to veto | ||
South Dakota | Legislature-dominant | Subject to veto | ||
Tennessee | Legislature-dominant | Subject to veto | ||
Texas | Legislature-dominant | Subject to veto | ||
Utah | Legislature-dominant | Subject to veto; advisory commission | ||
Vermont | Legislature-dominant | Subject to veto; advisory commission | ||
Virginia | Hybrid | N/A | A commission divided evenly between politicians and non-politicians drafts maps. The General Assembly must vote to approve the maps without amending them. If the General Assembly rejects the first set of draft maps, the commission must submit another. If the General Assembly rejects this second set of draft maps, the Virginia Supreme Court is tasked with enacting new maps. | |
Washington | Commission | Non-politician commission | ||
West Virginia | Legislature-dominant | Subject to veto | ||
Wisconsin | Legislature-dominant | Subject to veto; advisory commission | ||
Wyoming | Legislature-dominant | Subject to veto | ||
Sources: All About Redistricting, "National Summary," accessed July 29, 2024, The American Redistricting Project, "State," accessed July 29, 2024, NCSL, "Redistricting Commissions: State Legislative Plans," December 10, 2021 |
A redistricting commission is a body vested with the authority to draft and implement electoral district maps. The composition and operation of these commissions varies from state to state, reflecting the unique political dynamics and legal frameworks within each jurisdiction. In general, a redistricting commission can take one of two forms: politician commissions and non-politician commissions. Ballotpedia considers a politician commission to be any redistricting commission whose members can hold political office. A non-politician commission is any redistricting commission whose members can not hold political office. Note that Ballotpedia does not use the term "independent redistricting commission."
Redistricting commissions | ||||
---|---|---|---|---|
State | Type | Number of commissioners | Source | |
Alaska* | Non-politician | 5 | Source | |
Arizona | Non-politician | 5 | Source | |
Arkansas* | Politician | 3 | Source | |
California | Non-politician | 14 | Source | |
Colorado | Non-politician | 12 (two separate commissions for congressional and state legislative redistricting, each with 12 members) | Source | |
Hawaii | Non-politician | 9 | Source | |
Idaho | Non-politician | 6 | Source | |
Michigan | Non-politician | 13 | Source | |
Missouri* | Politician | 20 (House); 20 (Senate) | Source | |
Montana | Non-politician | 5 | Source | |
New Jersey | Politician | 13 (congressional); 10-11 (state legislative) | Source, Source | |
New York** | Non-politician | 10 | Source | |
Ohio* | Politician | 7 | Source | |
Pennsylvania* | Politician | 5 | Source | |
Virginia** | Both politician & non-politician | 16 | Source | |
Washington | Non-politician | 5 | Source | |
*State legislative redistricting only. **State uses hybrid redistricting methods. |
As of August 2021, twelve states required redistricting authorities to count prison inmates who are state residents at their pre-incarceration address, rather than in the community where their detention facility is located. Eleven states had those policies take effect with the 2020 redistricting cycle, while Illinois' policy was not scheduled to go into effect until 2025.[38][39] President Joe Biden (D) won all 12 of these states in the 2020 presidential election.
These states differed on whether their policy for counting incarcerated persons in their pre-incarceration districts applied to legislative or congressional maps. Five states counted incarcerated persons at their pre-incarceration addresses for legislative maps only, and seven counted them at their pre-incarceration residences for both legislative and congressional maps.
The states' policies also differed on how out-of-state inmates, and inmates with unknown previous residences, are counted. Two states—Colorado and Virginia—count these people as residents in their correctional facility for redistricting purposes. Seven exclude this group from all district redistricting population calculations. Connecticut counts these inmates as generic residents of the state, and Nevada’s policies do not address the issue. Pennsylvania excluded out-of-state inmates from all district population calculations, but counted in-state inmates with unknown previous residences as residents of their correctional facility.
Federal inmates are counted the same as state inmates in six states, and are excluded from redistricting calculations in two states. Four states have not addressed how to count persons incarcerated in federal facilities for redistricting.
The table below lists redistricting bills introduced during or carried over to each state's regular legislative session this year. The following information is included for each bill:
Bills are organized by state and then by most recent action. The table displays up to 100 results. To view more bills, use the arrows in the upper-right corner. Clicking on a bill will open its page on Ballotpedia's Election Administration Legislation Tracker, which includes bill details and a summary.
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