The Ohio Constitution grants the state supreme court exclusive jurisdiction over lawsuits challenging congressional and state legislative maps, Ohio Const. art. XIX, § 3(A) (congressional); Ohio Const. art. XI, § 9(A) (legislative), which the state supreme court has interpreted to include partisan gerrymandering claims, see Adams v. DeWine, 195 N.E.3d 74, 79 (Ohio 2022) (congressional); League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 192 N.E.3d 379, 403–07 (Ohio 2022) (legislative) (“League I”).
In 2015, Ohioans approved a ballot measure that amended the state constitution to include two express anti-gerrymandering provisions for legislative maps: The first prohibits them from “primarily . . . favor[ing] or disfavor[ing] a political party,” Ohio Const. art. XI, § 6(A), while the second requires “[t]he statewide proportion of districts whose voters, based on statewide state and federal partisan general election results during the last ten years, favor each political party shall correspond closely to the statewide preferences of the voters of Ohio,” id. art. XI, § 6(B). Three years later, voters approved another ballot measure that amended the state constitution to include an anti-gerrymandering provision for congressional maps that is similarly worded to Art. XI, § 6(A); it bars such maps from “unduly favor[ing] or disfavor[ing] a political party or its incumbents.” Id. art. XIX, § 1(C)(3)(a).[1]
To prove a claim for partisan gerrymandering against a congressional map, a plaintiff must show beyond a reasonable doubt that the “plan [] favors or disfavors a political party or its incumbents to a degree that is in excess of, or unwarranted by, the application of . . . specific line-drawing requirements to Ohio’s natural political geography.” Adams, 195 N.E.3d at 82, 85 (citing Ohio Const. art. XIX, §§ 1(C)(3)(a), 1(C)(3)(c), 2)). Applying this standard, the Ohio Supreme Court struck down the state’s initial congressional map for the 2020 redistricting cycle, Adams, 195 N.E.3d at 100, along with a remedial plan, Neiman v. LaRose, 207 N.E.3d 607, 623 (Ohio 2023). The court relied upon various types of statistical evidence in support of these rulings, including outlier analysis, efficiency gap, mean-median gap, declination, and partisan symmetry. Adams, 195 N.E.3d at 85–92; Neiman, 207 N.E.3d at 615–21.
To prove a claim for partisan gerrymandering against a legislative map, a plaintiff must demonstrate beyond a reasonable doubt either that the plan intentionally “favor[s] or disfavor[s] a political party,” League I, 192 N.E.3d at 400, 410 (quoting Ohio Const. art. XI, § 6(A)), or that the legislative map’s proportion of districts favoring a party does not “correspond to the statewide preferences of Ohio voters” expressed over the previous decade, id. at 407 (citing Ohio Const. art. XI, § 6(B)). The court will only strike down legislative maps for violating the Ohio Constitution’s partisan-fairness provisions for such maps if alternative plans can otherwise satisfy separate line-drawing requirements outlined in Art. XI, §§ 2, 3, 4, 5, and 7. See id. at 402. Applying these standards, the Ohio Supreme Court struck down the state’s initial legislative maps for the 2020 redistricting cycle, League I, 192 N.E.3d at 415, along with three remedial plans, League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 195 N.E.3d 974, 993 (Ohio 2022) (“League II”); League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 198 N.E.3d 812, 825–26 (Ohio 2022) (“League III”); League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 199 N.E.3d 485, 507 (“League IV”). As for demonstrating violations of Art. XI, § 6(A), the Ohio Supreme Court has recognized that “direct or circumstantial evidence may establish that a districting plan was drawn primarily to favor one political party over another.” League I, 192 N.E.3d at 410 (citing cases). According to the court, the following evidence collectively demonstrated a violation of Art. XI, § 6(A): domination of the map-drawing process by one party, statistical partisan symmetry analysis, and comparisons to neutral maps, including those that show the adopted plan is a statistical outlier among other possible plans. Id. at 410–12; League II, 195 N.E.3d at 985–89; League III, 198 N.E.3d at 820–23; League IV, 199 N.E.3d at 497–502. The court concluded the same types of statistical analysis prove violations of Art. XI, § 6(B). See League I, 192 N.E.3d at 407–09; League II, 195 N.E.3d at 990–93; League III, 198 N.E.3d at 824–25; League IV, 199 N.E.3d at 502–03. For the 2020 redistricting cycle, the court concluded that the legislative maps failed to comply with Art. XI, § 6(B) in large part because they disparately allocated competitive districts to one party. League I, 192 N.E.3d at 408; League II, 195 N.E.3d at 990–93; League III, 198 N.E.3d at 824–25; League IV, 199 N.E.3d at 502–03.
The Ohio Supreme Court, however, has held that the state constitution prohibits it from implementing or enforcing any particular remedial state legislative map. League IV, 199 N.E.3d at 503 (citing Ohio Const. art. XI, § 9(D)(1)–(2)). The court has yet to rule on whether a similar limitation applies to congressional maps. Of note, although the Ohio Constitution states that the legislature and then (if necessary) the Ohio Redistricting Commission should have an opportunity to produce a revised congressional map, the constitution does not specifically forbid the court from implementing or enforcing particular congressional maps, as the constitution does for legislative plans. Ohio Const. art. XIX, § 3(B)(1)–(2).
After the Ohio Supreme Court struck down the Commission’s revised congressional map for the 2020 redistricting cycle, which the Commission adopted once the legislature failed to enact a remedial plan, Neiman, 207 N.E.3d at 623, the U.S. Supreme Court, in light of its decision in Moore v. Harper, 600 U.S. 1 (2023), vacated the Neiman ruling, Huffman v. Neiman, 143 S. Ct. 2687 (2023). The petitioners then dismissed their case, leaving the revised congressional plan in place for the remainder of the decade. Entry, Neiman v. LaRose, No. 2022-0298 (Ohio Sept. 7, 2023).
Following the Ohio Supreme Court’s decision in League IV, which rejected the Ohio Redistricting Commission’s third set of remedial legislative maps for the 2020 redistricting cycle, the Commission readopted the plans the court struck down in League III, prompting the court to reject them for a second time. League of Women Voters of Ohio v. Ohio Redistricting Comm’n, 200 N.E.3d 197, 200 (Ohio 2022) (“League V”). After the Commission refused to produce a fourth set of revised maps, a federal court implemented the plans the Ohio Supreme Court found unconstitutional in League III for the 2022 election cycle only. Gonidakis v. LaRose, No. 2:22-CV-0773, 2022 WL 1709146, at *1 (S.D. Ohio May 27, 2022). In September 2023, the Commission produced another set of remedial maps that will be in use for the remainder of the decade. League of Women Voters of Ohio v. Ohio Redistricting Comm’n, No. 2021-1193, — N.E.3d —-, 2023 WL 8183694, at *4 (Ohio Nov. 27, 2023) (“League VI”).
Endnote
[1] This latter ballot measure also provided the jurisdictional grant for challenges to congressional maps. 2018 Ohio Laws Statewide Issue 2018 Statewide Issue No. 1 (May election) (Sub. S.J.R. 5) (codified at Ohio Const. art. XIX, § 3).