The Oregon Constitution grants the state supreme court original jurisdiction over lawsuits challenging state legislative maps, Or. Const. art. IV, § 6(2), which the state supreme court has interpreted to include partisan gerrymandering claims, see Sheehan v. Or. Legislative Assembly, 499 P.3d 1267, 1270–72 (Or. 2021). As for congressional maps, a special judicial panel has original jurisdiction over challenges to them with a right of appeal to the Oregon Supreme Court. Or. Rev. Stat. Ann. § 188.125(7), (9)(b), (10)(b), (11)(a). While the Oregon Supreme Court has yet to determine whether this grant of jurisdiction covers claims for partisan gerrymandering, a special judicial panel has concluded that it does. See Clarno v. Fagan, No. 21CV40180, 2021 WL 5632371, at *1 (Or. Cir. Ct. Nov. 24, 2021).
In 1979, the Oregon legislature enacted a provision that requires congressional and state legislative maps comply with certain line-drawing requirements, such as contiguity, maintenance of communities of interest, and the requirement that “[n]o district shall be drawn for the purpose of favoring any political party, incumbent legislator or other person.” Or. Rev. Stat. Ann. § 188.010. To establish unlawful partisan gerrymandering, a plaintiff must show that “[the legislature] either did not consider [the anti-gerrymandering provision set out in Or. Rev. Stat. Ann. § 188.010] or, having considered [it], made a choice or choices that no reasonable [reapportioning body] would have made.” Sheehan, 499 P.3d at 1270 (internal quotation marks and citation omitted).
Applying this standard, the Oregon Supreme Court rejected a challenge to the Oregon legislature’s legislative maps for the 2020 redistricting cycle, finding the following evidence insufficient to prove the petitioners’ partisan gerrymandering claim: (1) the plans’ reliance on previous district boundaries, (2) the legislature’s “focus on ‘partisan’ maps,” (3) the legislature’s failure to accept oral testimony about certain maps, and (3) the distribution of Republican and Democratic voters in several adjacent districts. Id. at 1271–72.
No constitutional or statutory provision expressly outlines the process for remedying an unlawful congressional partisan gerrymander, but for state legislative maps, the Oregon Constitution directs the secretary of state to produce a remedial map, subject to the Oregon Supreme Court’s review. Or. Const. art. IV, § 6(2).