Partisan gerrymandering is the configuring of election districts to advantage one political party over the other. The Supreme Court will address the constitutionality of that practice in one of the most highly anticipated cases of the current term.

Gill v. Whitford concerns the statewide redistricting plan adopted by the Wisconsin State Legislature in 2011 (Act 43). The plaintiff-appellees are a group of Wisconsin voters; they argue that Act 43 was passed by a Republican-controlled legislature for the purpose of entrenching the Republican legislators and that it unconstitutionally dilutes the voting strength of Democratic voters statewide. Specifically, appellees alleged that Act 43 illegally employed two gerrymandering techniques: “cracking”—dividing concentrated members of a political party into multiple districts so that they fail to reach a majority; and “packing”—joining members of a political party into one district, even if geographically disconnected, so that they win more easily.

The court will need to determine whether (and how) gerrymandering for partisan reasons, as opposed to racial discrimination or other goals, is regulated by the Constitution. Appellees claim that Act 43 violates the First Amendment and Equal Protection Clauses. By contrast, appellants (state officials) primarily argue that appellees lack standing to bring this claim because they do not reside in all the specific gerrymandered districts, and further that partisan gerrymandering claims are not justiciable because there is no workable standard to determine when a district is unconstitutional for being “too partisan.”

A three-judge court for the Western District of Wisconsin held that Act 43 was unconstitutional. The court determined: that Act 43 is an intentional partisan gerrymandered plan that dilutes the effectiveness of voters on the basis of political affiliation, that Act 43 has that effect based on state-wide elections in 2012 and 2014, and that Act 43 cannot be justified on other, legitimate legislative grounds.

On Oct. 3, the Supreme Court heard oral argument in this case. The arguments primarily addressed whether appellees have proposed judicially manageable standards for resolving partisan gerrymandering claims. In prior cases, the Supreme Court has declined to entertain such claims as nonjusticiable political questions. As appellants argue, a certain degree of partisan gerrymandering is inevitable and has been permitted since the founding of our country. This is particularly true when map-drawers are utilizing other traditional redistricting tools, such as contiguity, respecting communities of interest, and one-person-one-vote.

At oral argument, several Justices addressed Wisconsin’s argument that clear standards could not be applied to partisan gerrymandering claims. Justice Stephen Breyer proposed a multi-layered test that questions whether one party controlled redistricting alone, then whether the map treats the parties differently (and in that sense is asymmetrical), then whether the asymmetry is persistent over a range of votes and not merely outlier elections, and finally whether there is a justification or other motive. Justice Breyer questioned whether updated and more sophisticated voting technology has made it easier to answer these questions and create a workable standard for courts to use. Justice Elena Kagan similarly suggested that technology has made analyzing voting and redistricting scientific: “This is not the kind of hypothetical, airy-fairy, we guess, and then guess again.” Justice Sonia Sotomayor agreed that the updated technology was actually used in this case to create the most partisan redistricting map possible. She questioned, “if it’s the most extreme map they could make, why isn’t that enough to prove partisan asymmetry and unconstitutional gerrymandering?” Appellants’ counsel argued that the voting analysis is based on estimates and conjectures, which is appropriate for legislatures to consider, but not for courts. He argued that there remains no judicially manageable standard.

Some Justices expanded that theme and contended that endorsing partisan-gerrymandering cases with vague standards would harm the integrity of the court itself. Chief Justice Roberts expressed concern about “the intelligent man on the street” who would consider the social science and technological voting analysis as “baloney,” and that this man would believe “it must because the Supreme Court preferred the Democrats over the Republicans.” Chief Justice Roberts questioned whether it was appropriate to take districting away from the accountable, political branches of government and to throw these issues to the court based on “sociological gobbledygook.”

Appellees faced tough questioning about their standing to bring this claim. Roberts appeared unconvinced that members of a political party had enough of an interest to challenge gerrymandered districts in which they do not reside. Similarly, Justice Samuel Alito likened the case to racial vote-dilution cases under Section 2 of the Voting Rights Act that require plaintiffs to reside in the particular district at issue. Kagan countered that “one-person-one-vote” cases, in which members of an overpopulated district challenge a statewide districting scheme, are a closer analogy to partisan gerrymandering than Section 2 vote-dilution cases.

Focusing on the substance of partisan gerrymandering claims, Justice Anthony Kennedy questioned whether it would be unconstitutional for a state law to require that all factors must favor a specific political party in districting. Appellants’ counsel agreed that such a law would be unconstitutional under the Equal Protection Clause or the First Amendment. Counsel tried to argue that partisan gerrymandering has positive values because voters can understand more easily who represents them, and their representatives are therefore more accountable. Justice Sotomayor dismissed that contention and questioned whether there was any legitimate value to “stack the decks” for a political party.

As with other high-profile cases in recent years, it appears likely that the result will come down to Justice Kennedy’s vote. His concurrence in a prior partisan gerrymandering case, Vieth v. Jubelirer (U.S. 2004), suggested his willingness to consider such a challenge if plaintiffs could sufficiently set forth a “limited and precise” standard for adjudicating such challenges. The parties’ ability to convince Justice Kennedy on that issue will likely determine the outcome of this case.