The Pennsylvania Supreme Court has held that partisan gerrymandering claims are justiciable. 1991 Penn. Legislative Reapportionment Comm’n, 609 A.2d 132, 142 (Pa. 1992), abrogated in part on other grounds by Holt v. 2011 Legislative Reapportionment Comm’n, 38 A.3d 711 (Pa. 2012); see also Pa. Const. art. II, § 17(d) (granting the Pennsylvania Supreme Court original jurisdiction over challenges to state legislative maps).
According to the court, partisan gerrymandering claims are cognizable under the state constitution’s Free and Equal Elections Clause. League of Women Voters v. Commonwealth, 178 A.3d 737, 814 (Pa. 2018) (“League I”) (citing Pa. Const. art. I, § 5). To prove a claim for partisan gerrymandering, a plaintiff must demonstrate that the map subordinates traditional redistricting criteria, which include “compactness, contiguity, minimization of the division of political subdivisions, and maintenance of population equality among [] districts,” to “gerrymandering for unfair partisan political advantage[.]” Id. at 816–17.[1] Though this test does not require a showing of intent, the plaintiff must prove that the partisan gerrymander “clearly, palpably, and plainly violates the [state] [c]onstitution.” Id. at 801 (citation omitted). Applying this standard and relying on an evidentiary record developed by a trial court, the Pennsylvania Supreme Court struck down the state’s congressional map for the 2010 redistricting cycle. According to the court, arguably “the most compelling evidence” of partisan bias was statistical outlier analysis demonstrating that the plan at issue was less compliant with traditional redistricting criteria than any other simulated map. Id. at 818. The court also considered other types of statistical evidence, including mean-median gap and efficiency gap, along with its own assessment of the map, to conclude that the plan was an unconstitutional partisan gerrymander. Id. at 819–20. The court later applied its anti-gerrymandering standard when selecting a congressional map for the 2020 redistricting cycle after the state legislature and the governor failed to agree on a new plan. Carter v. Chapman, 270 A.3d 444, 461 (Pa 2022.), cert. denied sub nom. Costello v. Carter, 143 S. Ct. 102 (2022) (applying this standard when selecting a new congressional map for the 2020 redistricting cycle).
No constitutional or statutory provision expressly outlines the process for remedying an illegal congressional partisan gerrymander. However, the Pennsylvania Supreme Court has ruled that the court can implement a remedial congressional map after providing the legislature with an initial opportunity to do so. League I, 178 A.3d at 824. After the court struck down Pennsylvania’s congressional plan for the 2010 redistricting cycle and the legislature declined to adopt a revised one, the court implemented a map of its own. League of Women Voters of Penn. v. Commonwealth, 181 A.3d 1083, 1084 (Pa. 2018) (“League II”). With the assistance of a court-appointed advisor, the court produced a map that “dr[ew] heavily upon the submissions provided by the parties, intervenors, and amici” and that conformed with traditional redistricting criteria. Id. at 1085, 1087. As for state legislative maps, the Pennsylvania Constitution requires the state supreme court to remand maps found “contrary to law” back to Pennsylvania’s Legislative Reapportionment Commission, which draws the state’s legislative plans each redistricting cycle. Pa. Const. art. II, § 17(d). If the Commission fails to produce a revised map, the Pennsylvania Supreme Court must prepare its own map. Id. art. II, § 17(h). The Pennsylvania Supreme Court has not considered how to apply this remedial provision to a legislative map containing an illegal partisan gerrymander since it has yet to find one.[2]
Endnotes
[1] The Pennsylvania Supreme Court has left open the possibility that there might be other means of proving Free and Fair Elections Clause violations. Id. at 817.
[2] Though the court has ordered the implementation of a revised legislative plan after it struck down the initial plan for failing to abide by traditional redistricting criteria. Holt, 38 A.3d at 718.