Political gerrymanders predate the founding of the United States.1 However, the judicial branch has yet to develop a coherent approach to delineating the constitutional limits of partisan gerrymanders. In fact, in 2004, a plurality of Justices in Vieth v. Jubelirer2 resigned themselves to the idea that partisan gerrymandering claims are nonjusticiable because “no judicially discernible and manageable standards for adjudicating political gerrymandering claims have emerged.”3 However, in his concurrence, Justice Kennedy held out hope for judicial review, challenging lower courts to search for the kind of standard that the plurality had given up on finding.4 Recently, in Whitford v. Gill,5 a three-judge panel of the U.S. District Court for the Western District of Wisconsin outlined a method for evaluating claims of partisan gerrymandering and struck down a state redistricting scheme as unconstitutionally partisan.6 By narrowly defining the degree and duration of partisan advantage that would rise to the level of invidiousness and employing an innovative measure of voting power, the majority put forth a discernible and manageable standard for assessing claims of partisan gerrymandering.
When population changes reported in the 2010 census prompted the redrawing of state legislative district lines in Wisconsin, Republicans held a majority in both houses of the state legislature, and a Republican was governor.7 Reapportionment schemes must ensure districts maintain roughly equal populations to satisfy the Fourteenth Amendment’s one-person, one-vote requirement.8 District lines must also comply with traditional criteria like contiguity and compactness9 and with requirements of the Voting Rights Act.10
Over the course of several months, staff members of Republican legislative leaders11 drafted district maps that achieved varying levels of partisan advantage.12 The team used redistricting software that provided data on population demographics and current political boundaries to help them make decisions and to keep an eye on adherence to state and federal requirements.13 The drafters also used the software to create a metric to assess the partisan composition of new districts, confirming with a political science professor that their score was an accurate proxy for an area’s political makeup.14 That same professor provided the drafters with visuals depicting “the partisan performance of a particular map under all likely electoral scenarios.”15
Republican leadership reviewed several drafts of regional maps with the relevant partisan scores and chose drafts for each region.16 The drafters combined these selections to create the final map and performed additional partisan evaluations.17 The political science professor determined “that Republicans would maintain a majority under any likely voting scenario.”18 The final map and information about the partisan makeup of the voters in the relevant districts was presented to Republican legislators.19 The redistricting plan was passed by the state legislature, signed by the Governor, and published as Act 43 on August 23, 2011.20 In the 2012 election, Republicans won 60.6% of the assembly seats with just 48.6% of the statewide vote and, in the 2014 election, won 63.6% of the assembly seats with 52% of the vote.21
After these elections, plaintiffs — registered Wisconsin voters who “almost always vote for Democratic candidates” — alleged that Act 43 purposely and discriminatorily diluted Democrats’ votes statewide.22 In particular, they accused the state of employing gerrymander-ing techniques that “wasted”23 Democrats’ votes — both by spreading them out so they could not achieve a district majority (“cracking”) and by concentrating voters in a small number of districts to limit the number of seats their party could win (“packing”).24 This strategy, they claimed, constituted an unconstitutional gerrymander.25
A three-judge panel of the U.S. District Court for the Western District of Wisconsin agreed.26 Writing for the majority, Judge Ripple27 first engaged in a lengthy exegesis of Supreme Court precedent on gerrymandering,28 maintaining that precedent still held that “an excessive injection of politics is unlawful.”29 To identify excessive partisanship, the majority adopted the plaintiffs’ three-prong standard: a districting plan violates the Constitution if it “(1) is intended to place a severe impediment on the effectiveness of the votes of individual citizens on the basis of their political affiliation, (2) has that effect, and (3) cannot be justified on other, legitimate legislative grounds.”30
The majority then applied each prong of the test to Act 43. First, recognizing that precedent allows for some political considerations in redistricting and the political reality that partisan considerations will inevitably play some role,31 the majority needed to define intent in a way that created a rational dividing line between legal partisan considerations and invidious partisan gerrymandering. To accomplish this objective, the majority focused on a clear definition of the harm associated with unconstitutional partisan gerrymanders: entrenchment of power.32 The majority adopted a narrow definition of entrenchment as “making that party — and therefore the state government — impervious to the interests of citizens affiliated with other political parties.”33 The majority inferred the intent to entrench from the kinds of maps that were generated and the analysis that was undertaken.34
This anti-entrenchment principle guided the rest of the majority’s analysis as well. In assessing the effects prong, the majority reviewed election results from 2012 and 2014, as well as statistical analyses offered by expert witnesses, determining that the districting map had achieved its intended effect.35 The majority also employed a new measure called the Efficiency Gap (EG) to corroborate these findings. The EG evaluates the effect of a political gerrymander by comparing the number of wasted votes for each party: “Because the party with a favorable EG wasted fewer votes than its opponent, it was able to translate, with greater ease, its share of the total votes cast in the election into legislative seats.”36 The majority determined that Wisconsin’s pro-Republican EG of 13% for the 2012 elections and 10% for the 2014 elections demonstrated invidious partisan gerrymandering.37 Additional analysis demonstrated that an EG over 7% in the first election under a given plan would allow for partisan advantage to extend through the life of the districting scheme.38
With the first two prongs satisfied, the majority turned to the third prong, discussing possible justifications for the entrenchment caused by Act 43.39 In particular, the majority noted that Democrats’ tendency to live in more concentrated areas created a natural Republican advantage.40 But the majority found this justification insufficient: it did not “explain the magnitude of Act 43’s partisan effect, and . . . why the plan’s drafters created and passed on several less burdensome plans that would have achieved their lawful objectives in equal measure.”41
Judge Griesbach dissented.42 First, he took issue with the majority’s inclusion of intent in the test for partisan gerrymandering, noting that the Constitution should address political intent, if it needed to be addressed at all, by making a different body responsible for redistricting — an action outside the scope of the court’s authority.43 He also argued against the use of entrenchment as a touchstone for unconstitutionality, maintaining instead that a standard based on deviation from traditional districting criteria would be more acceptable to the Supreme Court.44
Finally, the dissent decried the majority’s “elevat[ion of] the efficiency gap theory from the annals of a single, non-peer-reviewed law review article to the linchpin of constitutional elections jurisprudence.”45 Judge Griesbach pointed to a series of shortcomings that rendered the EG measure unreliable. For example, on the theoretical side, the EG measure conceived of proportional representation as a right46 and mischaracterizes losing votes as wasted, even though “they shape the larger political debate.”47 Judge Griesbach also pointed to practical issues, including the EG measure’s volatile nature — created by the high number of wasted votes inherent in close races — and the fact that it can be significantly reduced by controlling for political geography.48
The Whitford majority effectively addressed key justiciability issues raised by the Supreme Court in Vieth, answering the Court’s call for a discernible and manageable standard for assessing constitutional claims of partisan gerrymandering. The majority confined its definition of entrenchment to the egregious facts at issue in this case and kept its standard grounded in clear and long-standing equal protection principles.49 In this way, the majority identified a dividing line between the inevitable and the invidious use of partisanship in the redistricting process. Furthermore, this definition and the assessment that the majority undertook — supported by the EG measure — evinces the standard’s manageability.
First, the anti-entrenchment principle at the foundation of the majority’s test offers a discernible dividing line between inherent and invidious gerrymandering. Even the Vieth plurality acknowledged that some level of partisan consideration is unconstitutional.50 Thus, the challenge left for lower courts was not establishing whether high levels of partisan consideration ever violated equal protection, but when the line was crossed. For decades, equal protection jurisprudence has focused on protecting against vote dilution.51 By its very nature, an anti-entrenchment principle — which looks for districting schemes that curtail the impact of shifts in voting — allows courts to identify and thus prevent the degradation of voting rights by partisan gerrymanders.52 By tying its standard to this cognizable constitutional harm, the majority established a discernible test.53
Additionally, given the degree and likely duration of the electoral advantage attained by the Republicans in this case, the majority was able to rely on a narrow definition of entrenchment and thus provide a more easily discernible standard than tests previously rejected by the Supreme Court.54 While acknowledging that less egregious or enduring schemes than those reached by its test might violate equal protection standards,55 the majority wisely avoided answering that broader question. Instead, the majority focused on the duration of voter disenfranchisement to establish definable bounds.56 While it chose not to identify an exact numerical threshold,57 the majority drew the line at the point when partisan advantage — intended and effectuated through a particular redistricting plan — will persist despite reasonable swings in parties’ vote shares.58 In establishing this line, the majority sidestepped a potential pitfall to which other proposed standards have fallen prey: indeterminacy.59 Whitford’s standard does not rely on “some indeterminate period.”60 Instead, it bases its assessment on likely outcomes for the duration of the district map at issue — that is, through the next decennial period.61
Furthermore, the anti-entrenchment principle does not demand proportional outcomes, which the Vieth plurality dismissed as not protected by the Constitution.62 While the dissent criticized the majority’s anti-entrenchment principle as requiring proportional representation,63 the question at the core of the anti-entrenchment principle is not whether outcomes are precisely proportional. Instead, it is whether disproportional outcomes are more or less fixed because one vote is more effective than another.64
Second, defining entrenchment by the durability of the districting scheme, the majority provided a standard that is manageable. Though the Court has not adopted clear criteria for assessing manageability,65 intelligibility is paramount.66 By providing a narrow understanding of entrenchment as a party maintaining control “under any likely future electoral scenario for the remainder of the decade,”67 the majority drew one line against which the constitutionality of districting schemes can be assessed.68 Even though this standard will not provide a clear answer to all partisan gerrymandering claims, this characteristic does not undermine the manageability of the test. Courts, drafters, and voters alike will still be able to identify “precisely what [courts are] testing for, [and] precisely what fails [this] test.”69
While the majority does not rely on the EG to find entrenchment,70 the measure shores up the standard’s viability by showing it to be susceptible to quantification and thus replication. In dismissing specific tests proposed in dissenting opinions, the Vieth plurality criticized Justice Souter’s test for not actually evaluating the level of vote dilution71 and Justice Breyer’s test for “provid[ing] no real guidance for the journey”72 to demonstrating “unjustified entrenchment.”73 A majority in Vieth also found that the Davis v. Bandemer74 effects test — which was the accepted standard for assessing partisan gerrymandering until Vieth — created an uncertain threshold focused on a group’s “chance to effectively influence the political process.”75 The standard did not identify the level at which lack of influence becomes unconstitutional.76 The EG measure helps the Whitford test avoid the ambiguity of these other tests by outlining the statistics to assess: the wasted votes of one party, the wasted votes of the other party, and the durability of partisan advantage over time.77
The Whitford majority established that there is a discernible distinction between the inevitable and the invidious use of partisanship in the redistricting process by adopting a narrow definition of entrenchment. With the support of the EG, the majority demonstrated the manageability of this standard. As a result, the majority successfully navigated the ambiguous and uncertain precedents currently governing partisan gerrymandering claims and showed that Justice Kennedy’s patience was justified.