by Alexi Comella*

Nearly sixty years ago in Reynolds v. Sims,1 the Supreme Court held that the Equal Protection Clause requires state and local legislative districts to be apportioned on a population basis. In other words, districts must contain equal populations. The Court has grounded this rule in advancing both voter equality and representational equality. Representational equality—the notion that each elected official should represent the same number of people—easily follows from Reynolds. However, voter equality—the idea that each district should have the same number of voters—seems to be in tension with this principle. Two districts with the same number of people may have different numbers of voters. Yet Reynolds raises voter equality as a rationale for its population apportionment rule. These seemingly contradictory justifications raise the question as to whether states may apportion their legislative districts according to a metric other than total population in order to achieve voter equality at the expense of representational equality. Such other metrics may include voter eligible population or the number of registered voters in a jurisdiction. This Contribution argues that the tension between voter equality and representational equality that pervades one person, one vote jurisprudence is already accommodated on the state and local level through the Court’s departure from requiring exact mathematic equality among those district populations.

The one person, one vote requirement for state and local legislative districting is justified on two grounds: voter equality and representational equality. While voter equality suggests that the same number of voters should reside in each state or local legislative district, representational equality rests on the idea that each elected official should represent the same number of people regardless of voting status. The tension between these two rationales raises the question of whether states may apportion their districts on a basis other than total population. Some point to this tension to assert that states should have the flexibility to apportion their legislative districts according to any rational population base. This Contribution will trace the history of the two rationales, then argue that because the Court does not require exact population equality among districts at the state and local level, both rationales are accommodated and flexibility for states already exists. Additionally, practical considerations weigh in favor of prioritizing equality of total population rather than any other metric in districting schemes.

The one person, one vote requirements for congressional districts versus state and local legislative districts have separate constitutional foundations, but share similar rationales. Wesberry v. Sanders established the one person, one vote requirement for congressional districts.2 There, voters in Georgia claimed that population disparities among congressional districts deprived them of “a right under the Federal Constitution to have their votes for Congressmen given the same weight as the votes of other Georgians.”3 The districts at issue had been drawn such that one district’s congressional representative represented two to three times as many people as other Georgia congress members.4 The Supreme Court held that “the command of Art. I, § 2, that Representatives be chosen ‘by the People of the several States’ means that as nearly as is practicable one man’s vote in a congressional election is to be worth as much as another’s.”5 Given that Article I, Section 2 commands congressional elections but not state or local elections, when faced with population disparities across Alabama’s state legislative districts in Reynolds v. Sims, the Court grounded the constitutional violation in the Equal Protection Clause.6 It held that “as a basic constitutional standard, the Equal Protection Clause requires that the seats in both houses of a bicameral legislature must be apportioned on a population basis.”7 The Wesberry and Reynolds holdings are collectively known as the “one person, one vote” requirement: they compel jurisdictions to design congressional, state, and local legislative districts with equal populations.8

Supreme Court jurisprudence interpreting the one person, one vote requirement is grounded in protecting both voter equality and representational equality. Voter equality calls for state or local districts to have the same number of voting residents. In contrast, representational equality is premised on ensuring one elected official represents the same number of residents as every other elected official within a particular jurisdiction, regardless of these residents’ ability to vote.9 Representational equality thus supports the notion of equalizing total population in districting schemes because all individuals, no matter their eligibility to vote, have a stake in the government that represents them.10 In contrast, voter equality may support equality of a different population, such as registered voters or eligible voters.11 In some jurisdictions, the number of voters may be proportional to the area’s total population. However, this is not the case in jurisdictions with large nonvoting populations.12 Thus, equalizing the number of people in state legislative districts may not equalize the number of voters, and vice versa. Without recognizing this tension, the Court at times points to debasement of the weight of a person’s vote as the constitutional violation in one person, one vote cases.13 In other instances, the Court identifies unequal representation in the legislature as the injury faced by those living in a district with more people than a neighboring district.14

Ambiguity in Supreme Court precedent regarding which principle of equality justifies its decisions in one person, one vote challenges to state and local districting schemes came to a head in Evenwel v. Abbott in 2016. The plaintiffs, Texas voters, pointed to portions of the Court’s opinions endorsing voter equality to support their assertion that state legislative districts in Texas should have been drawn with the goal of equalizing the state’s voter-eligible population, rather than total population.15 Nevertheless, the Court held that “a State may draw its legislative districts based on total population.”16 While the Court unanimously rejected the challengers’ claims, Justice Ginsburg, writing for the majority, acknowleded the tension in the Court’s case law, noting that “for every sentence appellants quote from the Court’s opinion, one could respond with a line casting the one-person, one-vote guarantee in terms of equality of representation, not voter equality.”17 Justice Thomas, concurring in the judgement, seized upon this acknowledgement to assert that the Constitution does not compel one vision of apportionment, but instead grants states the flexibility to equalize any rational population base.18

The flexibility Justice Thomas advocates for arguably exists. Together, total population-based apportionment and doctrinally permissible departures from exact mathematic equality among state and local legislative districts provide sufficient room for states to effect their own visions of apportionment.19

State and local legislative districts already have greater leeway in population apportionment than federal districts. In Gaffney v. Cummings, the Supreme Court considered a maximum total population deviation in Connecticut’s state senate districts of 1.81% and in the state’s house districts of 7.83%.20 The Court held that “minor deviations” from perfect mathematic equality among state legislative districts is not a violation of the Equal Protection Clause.21 The Court thus declined to hold state and local legislative districts to the same standard as congressional districts which permit only “limited population variances” of less than 1%.22 In so holding, the Court pointed to its decision in Reynolds which noted that “some distinctions may well be made between congressional and state legislative representation.”23 Those distinctions justify departure from strict compliance with mathematic equality so long as a rational state policy is effectuated.24 Importantly, the Gaffney Court also identified the tension that “‘census persons’ are not voters.”25 Therefore, perfect population apportionment between state legislative districts is not necessarily an identical representation of the weight of a person’s vote.26 Consequently, the Constitution does not require perfect equality of population among state and local legislative districts because of the divergence between a jurisdiction’s voter eligible population and total population.27

This discussion highlights that apportioning districts at the state and local level according to population equality, per existing Supreme Court precedent, effectuates both voter equality and representational equality. By apportioning state and local legislative districts using the metric of total population, deviations from mathematic equality may still occur when there are “legitimate considerations incident to the effectuation of a rational state policy,” such as the goal of advancing voter equality.28 In other words, the tension between voter equality and representational equality that pervades “one person, one vote” jurisprudence is accommodated through the Court’s departure from requiring exact mathematic equality among district populations at the state and local level.

Equalizing another metric besides total population—such as registered voters or voter eligible population—does not produce the same result, even after adjusting for permissible deviations from complete equality.29 Even if the Constitution “does not proscribe any one basis for apportionment within States,” as Justice Thomas contends, practical considerations weigh in favor of prioritizing equality of total population rather than other metrics in districting schemes.30 Every state in the country apportions their legislative districts using total population according to the decennial census.31 The census is an as-nearly-as-is-practicable complete enumeration of a jurisdiction’s population;32 however, in order to satisfy the constitutional mandate to apportion based on the “whole number of persons”33 every ten years, the Census Bureau is statutorily only required to measure the “tabulation of total population by States.”34 Other population measures are not nearly as precise or reliable as the total population count obtained through the census. For example, the citizen voting age population is derived from the American Community Survey (ACS). The ACS surveys 2.5% of households and only “give[s] ballpark estimates of previous citizenship rates, several years before redistricting is conducted.”35 Similarly, a count of registered voters necessarily excludes some citizens who are eligible to vote and is a metric that may be easily manipulated by the political process.36 Consequently, while states may certainly deviate from perfect mathematic equality in state and local districting schemes in order to advance voter equality to a certain extent,37 districting according to voter eligible population or registered voters in the first instance is impractical.

While there is certainly ambiguity throughout the Supreme Court’s jurisprudence interpreting the one person, one vote requirement of the Equal Protection Clause for state and local legislative districts, the goals of voter equality and representational equality can be reconciled under the Court’s existing caselaw. Precedent permits departure from exact mathematic equality among district populations at the state and local level, in contrast to the more stringent requirement of equality for congressional districting. Such departure allows states to apportion state and local legislative districts according to total population—thus achieving representational equality—while deviating from perfect mathematic equality of population in order to obtain greater voter equality.

* Alexi Comella is a J.D. candidate at New York University School of Law (2024). This Contribution was adapted from a paper originally written for Civil Rights & Civil Liberties, a seminar course at NYU Law taught by Professor Steven R. Shapiro in the Fall 2023. This Contribution does not necessarily represent the author’s views.

1. 377 U.S. 533, 560 (1964).

2. See generally, Wesberry v. Sanders, 376 U.S. 1 (1964).

3. Id. at 3.

4. Id. at 2.

5. Id. at 7–8.

6. Reynolds v. Sims, 377 U.S. 533, 560 (1964) (decided the same year as Wesberry, 376 U.S.).

7. Id. at 568.

8. See generally, Gray v. Sanders, 372 U.S. 368, 381 (1963) (holding Georgia’s county unit system for counting votes in primary elections unconstitutional and coining the term, “one person, one vote”).

9. See Semple v. Griswold, 934 F.3d 1134, 1146 (10th Cir. 2019) (Briscoe, J., Dissenting) (“[T]he principle of representational equality . . . ensur[es] that the voters in each district have the power to elect a representative who represents the same number of constituents as all other representatives.”).

10. See id. at 1141 (“Because elected representatives make decisions that affect both voting and nonvoting constituents, representation is equal when total population is equal.”).

11. See Chen v. City of Houston, 206 F.3d 502, 525 (5th Cir. 2000) (noting that “[i]f total population figures are used in an area in which potentially eligible voters are unevenly distributed,” the weight of eligible voters may be devalued).

12. See Brief for the United States as Amici Curiae Supporting Appellees, Evenwel v. Abbott, 578 U.S. 54 (2016) (No. 14-940) (“In many jurisdictions, the voter population diverges from the total population because of racially- and ethnically-correlated differences related to age, citizenship, and socioeconomic factors.”).

13. See Wesberry, 376 U.S. at 4 (“[I]n debasing the weight of appellants’ votes the State has abridged the right to vote for members of Congress guaranteed them by the United States Constitution.”); Lockport v. Citizens for Cmty. Action, 430 U.S. 259, 265 (1977) (“[T]he concept of equal protection therefore requires that [citizens’] votes be given equal weight.”).

14. See Reynolds, 377 U.S. at 565–66 (“[E]ach and every citizen has an inalienable right to full and effective participation in the political process of his State’s legislative bodies.”); Kirkpatrick v. Preisler, 394 U.S. 526, 530 (1969) (“[E]qual representation for equal numbers of people [is] the fundamental goal for the House of Representatives.” (internal quotation omitted)).

15. See Evenwel, 578 U.S. at 57.

16. Id. at 58 (emphasis added).

17. Id. at 71.

18. See id. at 76 (Thomas, J., concurring) (“The Constitution does not prescribe any one basis for apportionment within States. It instead leaves States significant leeway in apportioning their own districts to equalize total population, to equalize eligible voters, or to promote any other principle consistent with a republican form of government.”).

19. Due to the fact that the plaintiffs in Evenwel did not challenge the use of total population as a baseline in congressional districting, this Contribution is limited to consideration of apportionment for state and local legislative districts. See Evenwel, 578 U.S. at 62 n.5.

20. Gaffney v. Cummings, 412 U.S. 735 (1973).

21. Id. at 745.

22. Kirkpatrick, 394 U.S. at 531 (finding the Constitution allows only limited and unavoidable population variances); see also Karcher v. Daggett, 462 U.S. 725, 742–43 (1983) (holding that 1% disparity between population of New Jersey congressional districts is unconstitutional).

23. Reynolds, 377 U.S. at 578–79.

24. Gaffney, 412 U.S. at 748–49 (“Fair and effective representation may be destroyed by gross population variations among districts, but it is apparent that such representation does not depend solely on mathematical equality among district populations. There are other relevant factors to be taken into account and other important interests that States may legitimately be mindful of.”).

25. Id. at 746.

26. Id. at 746.

27. Id. at 748–49.

28. Reynolds, 377 U.S. at 579; see also Harris v. Ariz. Indep. Redistricting Comm’n, 578 U.S. 253, 255–56 (2016) (holding that those attacking a redistricting plan must show that a maximum population deviation of less than 10% reflected the predominance of illegitimate apportionment factors).

29. The Supreme Court has only once upheld an apportionment scheme that was based on a metric other than total population. See Burns v. Richardson, 384 U.S. 73 (1966) (upholding Hawaii’s interim districting plan that apportioned the state’s senatorial districts on the basis of registered voters). This decision was based on three factors unique to the dispute. First, Hawaii was home to several federal military establishments, presenting “special population problems” for the state’s apportionment scheme. Id. at 94. Second, the districting scheme was an interim plan adopted for use in the imminent 1966 general election. Id. at 85. Finally, the Court justified its conclusion that the interim apportionment scheme satisfied the Equal Protection Clause “only because . . . it was found to have produced a distribution of legislators not substantially different from that which would have resulted from the use of a permissible population basis.” Id. at 93 (emphasis added). The narrow language the Court used in evincing its holding in Burns is also due to concerns about the implications for using a metric other than total population in apportionment schemes. See id. at 92–93 (noting that the use of registered voter or actual voter base is susceptible to improper influences by those in power who may perpetuate “underrepresentation of groups constitutionally entitled to participate in the electoral process”). Thus, Burns v. Richardson supports the notion that total population is the most preferred districting metric.

30. Evenwel, 578 U.S. at 76.

31. See id. at 54.

32. See Fed’n for Am. Immigr. Reform v. Klutzkick, 486 F. Supp. 564, 567 (D.D.C. 1980).

33. U.S. Const. amend. XIV, § 2; see also id. art. I, § 2.

34. 13 U.S.C. § 141(b).

35. Nathaniel Persily, Who Counts for One Person, One Vote?, 50 U.C. Davis L. Rev. 1395, 1398 (2017).

36. See, e.g., Common Cause Ind. v. Lawson, 937 F.3d 944 (7th Cir. 2019) (affirming preliminary injunction which blocked Indiana law that sought to cleanse the state’s voter rolls of people the state believed were no longer eligible to vote); see also Kevin Morris, et al., Purges: A Growing Threat to the Right to Vote, Brennan Center for Justice (July 20, 2018), https://www.brennancenter.org/our-work/research-reports/purges-growing-threat-right-vote (finding that between 2014 and 2016, states removed nearly 16 million voters from their rolls).

37. See Harris, 578 U.S. at 259 (holding that those attacking a state-approved plan that has a maximum population deviation of less than 10% must prove that the deviation is based on illegitimate apportionment factors); see also Mahan v. Howell, 410 U.S. 315, 328 (1963) (holding maximum population deviation of more than 10% in Virginia was acceptable under the Equal Protection Clause because the plan “advance[d] the rational state policy of respecting the boundaries of political subdivisions”).