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Apportionment, Redistricting, and Gerrymandering

What are they?
How are they related?
Why are they important?

Apportionment

Article I, section 2, clause 31 of the Constitution requires not only that each state receive at least one representative, but also that each representative have a constituency of no more than 30,000 people.2  Following the first census,3 Congress passed the Apportionment Act of 1792.  It increased the number of House seats to maintain the ratio of one representative for every 30,000 people.  Thereafter, the size of the House increased regularly to keep pace with both the nation’s growing population and the addition of new states.  Eventually, practical considerations, such as the size of the House chamber, forced the ratio of constituents to representative to be waived.  The 1911 Apportionment Act responded to a large population increase and to Arizona and New Mexico joining the Union by increasing the House’s size to 433.  Partisan conflict following the 1920 Census, however, derailed the tradition for nearly the entire decade.4  The Permanent Apportionment Act was finally passed in 1929.  It fixed the number of House seats at 435, regardless of population growth or states entering the Union.  The Apportionment Act of 1941 stipulated that a mathematical formula, the Huntington-Hill Equal Proportions Method, be applied to determine each state’s number of representatives.  The formula assigns each state a priority value, which is calculated by multiplying the state’s population by a multiplier. 

On August 31, 1954, Congress passed Public Law 740, which established Title 13 of the U.S. Code.  Title 13 consolidates the rules and procedures pertaining to the Census Bureau, updating and codifying all prior legislation related to the census and establishing itself as the official and final word on all federal election matters.  Among other things, it requires that the Census Bureau begin the census by April 1; that the Secretary of Commerce deliver the completed census count and the number of representatives each state will have to the President by the end of December of the census year; that, within the first week of the next session of Congress, the President must report the apportionment population to the House Clerk; and finally that, within 15 days, the Clerk must submit the apportionment population and number of representatives that each state will receive to the state’s governor.  Any state may appeal to Congress the number of representatives allotted to it.  Once the number of representatives for a state has been determined, redistricting for the subsequent legislative elections (ie, even-numbered years) begins, as described below. 

Note that the District of Columbia is not a state.  Its population is counted, yet it does not have a voting representative in the House (it has a non-voting delegate), even though its population may exceed that of several states, viz Wyoming, Vermont and Alaska. 

Note also that, with the total number of representatives set at 435 and the requirement that each state receive at least one representative, not all districts across the country have equal populations.  If one divides 435 into the total US population — approximately 340 million — the average district constituency should be roughly 782,000.  Seven states, however, have only one representative, either because of the constitutional requirement, or because their populations failed to qualify them for a second representative.  When a state’s population puts it on the cusp for an additional seat but the formula denies it that seat, the state may appeal the House’s decision. 

Redistricting

Article I, section 4,5 of the Constitution empowers the states to determine how they will elect their representatives.  Theoretically, a state could choose to elect all its representatives by an at-large election.6  In practice, however, all states with multiple congress-members now elect them by district.  Currently, there are seven states with a single representative elected at-large: Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont and Wyoming. 

The states decide the process for redistricting, that is, redrawing district boundaries after a census.7  Many states assign the state legislature the responsibility for drawing district boundaries, though variations such as including or excluding the governor from the process, or using a redistricting commission in an advisory or back-up capacity, exist.  In Pennsylvania, for example, the General Assembly must pass a redistricting bill, which then must be signed by the Governor.  If the Governor vetoes the bill and is subsequently unable to reach a compromise redistricting plan with the legislature, then the Pennsylvania Supreme Court assumes responsibility.  The Court may commission an outside person or agency to draw the boundaries, or it may request submissions from interested individuals and organizations, and select a plan from among the submissions.8  Some states assign responsibility to redistricting commissions.9  The composition and method of choosing commission members varies across states.  The primary reason for any state to adopt a redistricting commission is to minimize the politicization of the process, that is, to eliminate gerrymandering (see below). 

A state that neither gains nor loses a House seat may also need to undertake redistricting due to population movement within the state.  Historically, Americans relocated from rural areas to cities, from cities to suburbs, and later from suburbs to exurbs as industrialization spread following the Civil War.  In the post-Civil War decades, however, many state legislatures neglected to redistrict.  Dominated by members from rural areas, these legislatures sought to limit the political influence of their states growing urban centers.  This caused malapportionment: districts with dramatically unequal populations.  In a malapportioned state, people living in a district with a very large population have significantly less voting power than those residing in a district with a smaller population.  In other words, the number of legislative seats is no longer proportional to the population in the districts.10 

Attempts to address malapportionment through state and federal courts have failed repeatedly.  In 1946, the US Supreme Court heard the case of Colegrove v. Green (328 US 549), in which the plaintiffs argued that the Illinois legislature’s failure to redistrict adequately created districts that left the state’s largest population centers — Chicago and East St. Louis — severely underrepresented.  The Court ruled that it could not involve itself in this matter because it was a political question —  that is, a question that is not a legal problem, but rather a political one that must be resolved by one or both political branches, namely the Congress and Executive. 
  Changes in the Supreme Court’s membership, however, saw the Court overturn Colegrove in 1962, when it decided Baker v. Carr (369 US 186).  Tennessee’s legislature had districts that diminished the voting power of people in its cities, notably Nashville, Memphis and Knoxville.  The Court ruled that it could hear malapportionment cases under the 14th Amendment’s Equal Protection clause, meaning that malapportionment would no longer be considered a political question.  Subsequently in 1964, the Court heard two landmark cases: Reynolds v. Sims (377 US 533) and Wesberry v. Sanders (376 US 1).  Reynolds concerned Alabama’s congressional districts, that plaintiffs argued were malapportioned.  The Court agreed, reasoning that the Equal Protection Clause guaranteed that each person’s vote should be weighted the same, and coining the famous phrase “one person, one vote.”  In Wesberry, the Court found that both chambers of Georgia’s state legislature were malapportioned, and declared that both houses should be apportioned and redistricted following the one person, one vote rule.11 
  The Supreme Court refined its rules on population apportionment in Karcher v. Daggett 462 US 725 (1983).  The case involved New Jersey’s redistricting plan following the 1980 census.  Its districts were roughly equal in population, but the Court declared that the districts’ populations were not sufficiently equal and hence must be redrawn to reduce inequality to less than 1%.  The Court also added that the districts must be contiguous (ie. whole or undivided), and compact (ie, not weirdly drawn or unrecognizably contorted in shape).  It also strongly suggested that, whenever possible, municipalities should not be divided (ie, a town, county or borough should not be split into two or more districts).  These Court decisions eliminated malapportionment as an issue, but they did not put an end to gerrymandering. 

Gerrymandering

The term gerrymandering12 applies to the practice of drawing a state’s legislative district boundaries to improve the odds of electing one party’s candidates (the party controlling the process) over any opposing parties’ candidates.  With advances in computer technology and the accumulation of detailed data on voters, it is now possible to devise exceedingly precise district maps that give maximum advantage to the party sketching the maps.  This is type of gerrymandering is sometimes referred to as partisan gerrymandering, because its motivation is purely political.  Racial gerrymandering occurs when a party dilutes the voting strength of people, frequently black Americans but also Asian, Latino and Native Americans, based on their race.  Occasionally, religious gerrymandering has been identified, but the Supreme Court has yet to recognize such claims as credible.13

Two strategies are involved in gerrymandering: cracking and packing.  With cracking, the victimized party’s voters happen to be geographically concentrated in one or more areas in a state.  The party engaged in gerrymandering will divide — crack — those areas so that the victimized party’s voters are diluted, mixing them into areas containing larger numbers of the gerrymandering party.  Packing, on the other hand, concentrates — packs — as many of the victimized party’s voters as possible in as few districts as possible, basically conceding those districts to the victimized party but also improving the chances of the gerrymandering party in many other districts.14

Efforts to find a constitutional remedy to end partisan gerrymandering have yet to succeed.  Beginning with Davis v. Bandemer 478 US 109 (1968), the Supreme Court decided that there was no appropriate judicial solution to the problem.15  In 2004, Democrats from Pennsylvania contended, in Vieth v. Jubelirer (541 US 167), that the congressional districts created by the GOP-dominated General Assembly were drawn only for partisan reasons, which violated the Equal Protection clause because it ensured the GOP would consistently win a majority of Pennsylvania’s congressional seats.  In a decision that failed to attain majority of the Justices, the Court decided not to intervene, invoking the reasoning in Davis v. Bandemer, namely that there was no appropriate judicial solution.  Justice Scalia, writing for four members, stated that the Court should declare all arguments related to partisan gerrymandering, but not racial gerrymandering, nonjusticiable; in other words, courts could neither entertain nor hear them.  The reasoning in Vieth was invoked by the Court in a 2019 case from North Carolina, Rucho v. Common Cause (139 US 2484), in which Chief Justice Roberts, writing for the five-person majority, stated that partisan gerrymandering was nonjusticiable because no judicial solution was available.  Partisan gerrymandering will likely remain in place for the foreseeable future.16

The Supreme Court has, however, been somewhat more sympathetic to charges of racial gerrymandering.  Over the decades since 1986, the Supreme Court heard several cases challenging congressional district maps from North Carolina.  In 1986, the state’s Republican-controlled legislature crafted a map with seven new districts, but the state’s black voters could not elect a black candidate in any of them.  A group of black citizens filed a suit in federal district court, arguing that the new map violated Section 2 of the 1965 Voting Rights Act17 as well as the 14th and 15th Amendments.  The district court found for the plaintiffs, stating that nearly all the districts discriminated against black voters, because they cracked black voting strength by moving black voters into predominately white areas.  North Carolina appealed to the Supreme Court, which ruled in Thornburgh v. Gingles, 478 US 30 (1986) that the map damaged the ability of black voters to “participate equally in the political process and to elect candidates of their choice.” 

Another North Carolina map was challenged and the case was decided by the Supreme Court in 1993: Shaw v, Reno 509 US 630.  Reno, the US Attorney General, rejected the state’s original map through the preclearance sections (4 and 5) of the Voting Rights Act, because the map contained only one district where blacks had any real chance of electing a black candidate.  The state drew a second map with two districts that favored black candidates, but one of the districts was not compact; in fact, it was two large areas connected by a thin strip of land that straddled an interstate highway.  Five white residents challenged the revised map, and the Shaw opinion found for the plaintiffs, because the district’s bizarre shape was sufficient to prove that it was constructed to only elect a black candidate, and therefore violated the 14th Amendment’s Equal Protection clause: white voters had been discriminated against. 

Following the 2010 census, Alabama drew a map that neglected to sufficiently reflect the voting strength of its black citizens.  US Attorney General Holder, invoking Sections 4 and 5 of the Voting Rights Act, rejected the map.  Shelby County leaders challenged Holder’s action.  In Shelby County v. Holder 570 US 529 (2013), the Court ruled that Section 4 was unconstitutional, because racism essentially was no longer an issue in America, so identifying counties as racist based on past behavior violated the 14th Amendment’s Equal Protection clause.  (Robert’s majority opinion mentioned that blacks now held many more elected position as evidence that race was a less important at that time.)

Since 2013, the Supreme Court has heard many other cases on this subject, with nearly all following the Shelby County reasoning.18  In the most recent case, Alexander v. South Carolina State Conference of the NAACP 602 US _ (2024), by a 6–3 vote, the Court overturned a federal district court’s ruling that Alabama’s 1st Congressional district was a racial gerrymander.  The Republican-controlled state legislature moved 30,000 black voters from the 1st District when it redrew its map following the 2020 census.  The lower court found the new map was based on an “impermissible racial target” because the legislators had a goal of limiting the number of black representatives.  In its defense, the state claimed the map reflected only a partisan — not a racial — goal: to limit the number of Democrats elected to Congress.  The Supreme Court’s decision said that the lower court’s analysis was “clearly erroneous.”  When race and political party choices are very highly correlated, the Court reasoned, the plaintiff must present overwhelming evidence that the “predominant factor” in creating the districts was racial and not political.  The plaintiffs’ failure to present an alternative map that could attain the state’s partisan goals without any racial effects, essentially concedes that the state’s political motivation was reasonable.  This decision makes it exceptionally difficult to prove racial gerrymandering, as black voters tend to register as Democrats.  When using voter registration data to draw a map that cracks Democratic voting strength, dilution of black voting strength is a coincidental effect. 

  1. “Representatives and direct taxes shall be apportioned among the several states which may be included within this Union, according to their respective numbers, which shall be determined by adding to the whole number of free persons, including those bound to service for a term of years, and excluding Indians not taxed, three fifths of all other persons …The number of representatives shall not exceed one for every thirty thousand, but each state shall have at least one Representative; …”  ⇧
  2. Because a census would not take place until 1790, a ratio was needed for the first elections for the number of people for each congressperson to represent.  There was some debate at the Constitutional Convention over that ratio, with some delegates arguing for 40,000 to 50,000 people.  In a rare instance of Washington publicly taking a position at the Convention, he supported 30,000 people, helping that figure carry the day.   ⇧
  3. Parts of Article I, section 2, clause 3 were superseded with the passage of the 14th Amendment’s section 2, which required the “counting of the whole number of persons in each state.”  In other words, all people, regardless of former condition of servitude, skin color, or citizenship status, shall be included in the population for purposes of determining a state’s number of representatives.   ⇧
  4. The 1920 House elections brought a Republican House majority.  Republicans attempted to pass an apportionment act that would have increased the number of seats to 483.  Democrats resisted, and the apportionment was delayed until 1929.   ⇧
  5. “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 choosing Senators.”   ⇧
  6. At-large elections were used in many states following the Constitution’s ratification because no census had been taken and states did not have the time or had not yet established the procedures to draw district boundaries.  After the 1790 Census, however, those states with multiple congressional seats decided to draw their districts, and thereafter elected its representatives by districts.   ⇧
  7. Because each state must also redistrict its state legislature, each state determines the method by which it will conduct that redistricting.  The process is usually found in a state’s constitution, with the methods as varied as those employed to draw congressional districts.  Some states use different methods for their state legislatures and their congressional seats.  Pennsylvania uses a reapportionment commission composed of five members: the majority and minority party leaders from each chamber and a fifth member, chosen by the four, who acts as the chairperson.  Should the four members be unable to agree on the chair, the state’s Supreme Court selects the chair.  ⇧
  8. The latter occurred following the 2020 census, when the Governor and General Assembly deadlocked over the issue.  The high court solicited redistricting plans from any interested party with expertise.  More than a dozen plans were submitted, including the map drawn by the General Assembly.  On February 23, 2022, the Court, by a vote of 4 to 3, chose a map drawn by a group of private citizens. 
      Leading up to this impasse, Republicans controlled the General Assembly and the Governor’s office after the 2010 census.  The congressional map dramatically favored the GOP; it included the infamous “Goofy kicking Donald” district in the southeast.  In June of 2017, the Pennsylvania League of Women Voters went to the Pennsylvania Supreme Court, arguing that the map was unconstitutionally gerrymandered, and on January 22, 2018, the Court agreed with the League, rejecting the map.  The Court then commissioned an outside expert to draw a political balanced map, which was used to hold the May 2018 primaries, the November general election, and all subsequent elections until the 2022 map was adopted.   ⇧
  9. Currently, these states are Arizona, California, Colorado, Hawaii, Idaho, Michigan, Montana, New Jersey, Virginia, and Washington.   ⇧
  10. Here is an example.  A state has five districts.  In three districts, the population is 100 people, and in the remaining two, the population is 1000 people. The voting power of the people in the smaller districts is therefore ten times greater than in the larger districts; hence their votes carry ten times more weight.   ⇧
  11. By 1964, most states with upper chambers modeled on the US Senate did not redraw their upper chamber’s districts, typically based on counties, because, like the US Senate, representation reflected the county not the number of people.  Note also here that the US Senate is an inherently malapportioned body.  Regardless of a state’s population, it holds two Senate seats.  Wyoming, the least populated state, has the same voting strength and representation in the Senate as California, the state with the largest population.   ⇧
  12. The term gerrymandering comes to us from Massachusetts’ 1812 redistricting.  The state’s governor, Elbridge Gerry, a Democratic-Republican (Jefferson’s party), signed a new congressional map passed by the state’s legislature, dominated by Democratic-Republicans.  The map heavily favored their party.  One of the districts that included Boston appeared to resemble a salamander.  On March 26, 1812, the Boston Gazette, a Federalist newspaper, published a cartoon of that district that added claws to its “feet”, wings, and eyes, teeth and a tongue to its “head.”  The creation was labeled a “Gerry-mander.”  Although the term’s author has not been conclusively identified, the cartoon was probably devised by Elkanah Tisdale, an artisan living in Boston.  (The engraving’s woodblock is held in the Library of Congress.) Despite their effort to gerrymander their way to victory, the Democratic-Republicans lost the Massachusetts state House to the Federalists, and Gerry was denied his reelection bid.  The Party did win the state Senate, however.   ⇧
  13. Rosen, Jacqueline.  “Religious Gerrymandering: A New Avenue for Redistricting Challenges?”  Election Law Journal: Vol. 22, No. 1, 2023.  See also the Supreme Court decision in United Jewish Organizations of Williamsburgh v. Carey 430 US 144 (1977).  ⇧
  14. One may find any number of gerrymandering simulations online, from which one can better understand how packing and cracking operate.  For example, see this New York Times article.   ⇧
  15. The plaintiffs, Democrats living in Indiana, argued that the congressional map drawn by the Republican-controlled legislature disenfranchised them because the total vote received by all Democratic candidates across the state was larger than the Republican state-wide vote yet the proportion of seats won by the Democrats was significantly below the number of seats won by the GOP’s candidates.  In a 7–2 vote, the Court found that the Democrats were not disenfranchised because they were allowed to cast votes and their votes were counted.  The 14th Amendment’s Equal Protection clause did not guarantee electoral success.   ⇧
  16. In 2025, Republican-controlled legislatures in Texas and Missouri passed redistricting bills that could potentially increase the number of GOP seats by five in Texas and one in Missouri.  At the time of this writing, California and New York are considering redrawing their House districts to increase the number of districts that favor Democratic candidates.  These are highly unusually events.  The last mid-decade redistricting occurred in 2003 in Texas, with the same intent as the 2025 redistricting.   ⇧
  17. The Voting Rights Act was passed to protect voters of racial, ethnic, or physically challenged minorities.  It had been regularly updated and amended every 5 to 8 years by large bipartisan majorities in Congress, but not since 2006.  Section 2 prohibits any state or local government from adopting any law, rule or ordinance that “results in the denial or abridgment of the right of any citizen to vote on account of race or color” or membership in a minority group.  Also forbidden are literacy tests and grandfather clauses to prohibit voting.  Section 4 defined the conditions under which a state or parts of a state could be subject to Section 5’s preclearance requirement.  If a state or part of a state had a history of discriminating against any minority group by any means, that state or part of a state must submit to preclearance.  Preclearance under Section 5 requires a state or part of a state to submit its redistricting maps to the Justice Department’s Civil Rights division for review, to determine if racial gerrymandering is present.  If a state does not submit its map, the Attorney General can independently review the map, and can seek a court injunction to halt the use of a map that fails to meet the Section 2 requirements.  The latest attempt to renew the VRA is called the John R. Lewis Voting Rights Advancement Act.   ⇧
  18. The most important of these cases are Cooper v. Harris 581 US _ (2017); Easly v. Cromartie 532 US 234 (2001); Alabama Legislative Black Caucus v. Alabama 575 US _ (2015); and Allen v. Milligan 599 US _ (2023).   ⇧

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