Explainer: Status of Partisan Gerrymandering Claims Across the Country

Harry Isaiah Black, Staff Attorney

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Every 10 years, following the federal census, states are required to redraw their congressional and legislative district maps. In the majority of states, the duty to redistrict rests with the state legislature. Because line-drawing decisions can have significant electoral consequences, the redistricting process is often highly contentious. An especially prominent concern is with partisan gerrymandering—that is, the adoption of maps that unduly advantage one political party over another. This explainer assesses the rise of state court litigation as one important tool for curbing partisan gerrymandering.

Partisan gerrymandering litigation in state courts has proliferated in the wake of the U.S. Supreme Court’s 2019 decision in Rucho v. Common Cause,[1] which declared that federal constitutional challenges to partisan gerrymandering present nonjusticiable “political questions,” meaning that federal courts lack the power to resolve them. The Rucho Court, however, insisted that it had not “condemn[ed] complaints about districting to echo into a void,” noting the potential for “[p]rovisions in state statutes and state constitutions” to constrain gerrymandering.[2]

In recent years, a growing number of states have adopted statutory or constitutional provisions that specifically address partisan gerrymandering, including by expressly demanding partisan fairness and by shifting redistricting authority from partisan legislators to more politically insulated actors, such as independent redistricting commissions. Such anti-gerrymandering measures currently exist in 15 states.[3] They have been enacted primarily through direct democracy mechanisms, which are available in only about half of states.[4] Every state, however, has broadly worded state constitutional protections—such as guarantees of equal protections, free expression, and “free and equal elections”[5]—that litigants may attempt to invoke to challenge partisan gerrymanders.

During the 2020 redistricting cycle, plaintiffs have thus far filed partisan gerrymandering claims in 19 states, challenging congressional maps, state legislative maps, or both.[6] In some of these cases, the plaintiffs contend that maps violate specific state constitutional gerrymandering limitations, while in others they rely on broader state constitutional provisions and principles. Though some of those cases remain pending, several trends have emerged, especially when the case law from this redistricting cycle is considered with that from previous redistricting cycles.[7]

First, in contrast to the U.S. Supreme Court’s holding in Rucho that federal partisan gerrymandering claims are nonjusticiable, a majority of state supreme courts to have considered the issue (currently ten[8]) have held that state-law partisan gerrymandering claims can be adjudicated, whereas four supreme courts have determined that such claims are not justiciable.[9] In one state that falls in the latter group—Missouri—voters have since added a partisan fairness provision for legislative maps to the state constitution,[10] so partisan gerrymandering claims there might become viable going forward, at least as for legislative plans.

Second, the few state courts that have held partisan gerrymandering claims nonjusticiable post-Rucho have generally relied upon Rucho’s reasoning to make that determination.[11] Rucho’s holding rested on the premise that the federal Constitution lacked “discernible” standards for adjudicating partisan gerrymandering claims, “let alone limited and precise standards that are clear, manageable, and politically neutral.”[12] Echoing Rucho, these courts have also held that their constitutions lack adequate standards to resolve partisan gerrymandering claims.

Third, in the states that treat partisan gerrymandering claims as justiciable, most courts have required plaintiffs to prove partisan bias by demonstrating partisan intent, effects, or both,[13] though at least one court (the Alaska Supreme Court) has centered the inquiry on a map’s compliance or noncompliance with nonpartisan districting criteria, such as respecting territorial communities of interest.[14]

The remainder of this explainer surveys the case law from the states that have thus far issued rulings on partisan gerrymandering claims regarding congressional and legislative maps. For states in which courts have held that they can adjudicate such claims, the explainer, where possible, describes the standard the court applies to assess the legality of an alleged partisan gerrymander, along with the process for remedying an illegal partisan gerrymander. The explainer also covers states where the viability of partisan gerrymandering claims is unclear but where there are active or decided cases relevant to the issue.

Please click on the links below to explore the case law from states that have ruled on the justiciability of partisan gerrymandering claims and states in which the viability of those claims is unclear.


[1] 139 S. Ct. 2484, 2506 (2019).

[2] Id. at 2507.

[3] Arizona, California, Colorado, Delaware, Florida, Hawaii, Idaho, Iowa, Michigan, Missouri, Montana, New York, Ohio, Oregon, and Washington. See Samuel S.-H. Wang et al., Laboratories of Democracy Reform: State Constitutions and Partisan Gerrymandering, 22 U. Pa. J. Const. L. 203, 237 n.162 (2019), for a list of the provisions. Since that article was published, the Utah legislature repealed its anti-gerrymandering provision in the state code. A challenge to that repeal is pending before the Utah Supreme Court. League of Women Voters of Utah v. Utah State Legislature, No. 20220991-SC (Utah Nov. 14, 2022). And, since the article was published, Missouri voters amended their constitution in 2020 to limit the effect of a constitutional anti-gerrymandering provision initially passed in 2018 by prioritizing certain line-drawing requirements over partisan fairness. See S.J.R. No. 38, 2020 Mo. Legis. Serv. Sen. Jt. Res. 38 (Vernon’s) (codified at Mo. Const. art. III, §§ 3(b)(5), 7(c)).

[4] See Allie Boldt, Direct Democracy in the States: A 50-State Survey of the Journey to the Ballot 4-5, State Democracy Research Initiative, https://statedemocracy.law.wisc.edu/wp-content/uploads/sites/1683/2023/11/Direct-Democracy-In-the-States-Full-Report.pdf.

[5] See, e.g., Pa. Const. art. I, § 5 (“Elections shall be free and equal; and no power, civil or military, shall at any time interfere to prevent the free exercise of the right of suffrage.”).

[6] Alaska, Arkansas, Florida, Kansas, Kentucky, Maryland, Michigan, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Tennessee, Utah, and Wisconsin. See generally, The American Redistricting Project, https://thearp.org/litigation/ (last visited Feb. 28, 2024); All About Redistricting, https://redistricting.lls.edu/ (last visited Feb. 28, 2024); Democracy Docket, https://www.democracydocket.com/ (last visited Feb. 28, 2024).

[7] For additional analysis of state partisan gerrymandering litigation, see Yurij Rudensky, Status of Partisan Gerrymandering Litigation in State Courts, Brennan Center for Justice (Dec. 18, 2023), https://statecourtreport.org/our-work/analysis-opinion/status-partisan-gerrymandering-litigation-state-courts.

[8] The Alaska Supreme Court, Florida Supreme Court, Kentucky Supreme Court, Maryland Supreme Court, New Jersey Supreme Court, New Mexico Supreme Court, New York Court of Appeals, Ohio Supreme Court, Oregon Supreme Court, and the Pennsylvania Supreme Court.

[9] The Kansas Supreme Court, Missouri Supreme Court, New Hampshire Supreme Court, and the North Carolina Supreme Court. Although the West Virginia Supreme Court, in a pre­-Rucho case, has held that partisan gerrymandering claims are nonjusticiable, it has not clarified whether this holding applies only to federal constitutional claims or also extends to claims brought under the state constitution. State ex rel. Cooper v. Tennant, 730 S.E.2d 368, 388–90 (W. Va. 2012). The Wisconsin Supreme Court initially declined to consider partisan fairness when selecting remedial legislative maps because it “present[ed] a purely political question,” Johnson v. Wis. Elections Comm’n, 967 N.W.2d 469, 482 (Wis. 2021), but has since concluded that it should assess partisan fairness when adopting remedial maps, Clarke v. Wis. Elections Comm’n, 998 N.W.2d 370, 380 (Wis. 2023).

[10] See Mo. Const. art. III, § 3(b)(5) (requiring state house maps to achieve partisan fairness); id. art. III, § 7(c) (applying Art. III, § 3(b)(5)’s anti-gerrymandering provision to state senate maps).

[11] The Kansas Supreme Court, New Hampshire Supreme Court, North Carolina Supreme Court, and the Wisconsin Supreme Court. In Pearson v. Koster, the Missouri Supreme Court also concluded that partisan gerrymandering claims are nonjusticiable under the state constitution, but that decision was issued prior to Rucho. 359 S.W.3d 35, 41–42 (Mo. 2012).

[12] 139 S. Ct. at 2500.

[13] League of Women Voters of Fla. v. Detzner, 172 So. 3d 363, 375 (Fla. 2015); In the Matter of 2022 Legislative Districting of State, 282 A.3d 147, 160 (Md. 2022); Grisham v. Van Soelen, 539 P.3d 272, 289 (N.M. 2023); Harkenrider v. Hochul, 197 N.E.3d 437, 452 (N.Y. 2022); Adams v. DeWine, 195 N.E.3d 74, 85 (Ohio 2022); League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 192 N.E.3d 379, 410 (Ohio 2022); Sheehan v. Or. Legislative Assembly, 499 P.3d 1267, 1270 (Or. 2021); League of Women Voters v. Commonwealth, 178 A.3d 737, 801, 816–17 (Pa. 2018).

[14] In the Matter of 2021 Redistricting Cases, 528 P.3d 40, 88 (Alaska 2023).

This report was published in March 2024