The Future of Partisan Symmetry as a Judicial Test for Partisan Gerrymandering after LULAC v. Perry
Bernard Grofman and Gary King*
While the Supreme Court in Bandemer v. Davis found partisan gerrymandering to be justiciable, no challenged redistricting plan in the subsequent 20 years has been held unconstitutional on partisan grounds. Then, in Vieth v. Jubilerer, five justices concluded that some standard might be adopted in a future case, if a manageable rule could be found. When gerrymandering next came before the Court, in LULAC v. Perry, we along with two of our colleagues filed an Amicus Brief (King et al., 2005), proposing the test be based in part on the partisan symmetry standard. Although the issue was not resolved, our proposal was discussed and positively evaluated in three of the opinions, including the plurality opinion, and for the first time for any proposal the Court gave a clear indication that a future legal test for partisan gerrymandering will likely include partisan symmetry. A majority of Justices now appear to endorse the view that the measurement of partisan symmetry may be used in partisan gerrymandering claims as “a helpful (though certainly not talismanic) tool” (Justice Stevens, joined by Justice Breyer), provided one recognizes that “asymmetry alone is not a reliable measure of unconstitutional partisanship” and possibly that the standard would be applied only after at least one election has been held under the redistricting plan at issue (Justice Kennedy, joined by Justices Souter and Ginsburg). We use this essay to respond to the request of Justices Souter and Ginsburg that “further attention … be devoted to the administrability of such a criterion at all levels of redistricting and its review.” Building on our previous scholarly work, our Amicus Brief, the observations of these five Justices, and a supporting consensus in the academic literature, we offer here a social science perspective on the conceptualization and measurement of partisan gerrymandering and the development of relevant legal rules based on what is effectively the Supreme Court’s open invitation to lower courts to revisit these issues in the light of LULAC v. Perry.
The U.S. Supreme Court declared partisan gerrymandering claims justiciable in Davis v. Bandemer,1 but in the subsequent two decades no redistricting plan has been struck down as an unconstitutional partisan gerrymander. In Vieth v. Jubilerer,2 five Justices concurred that the challenged Pennsylvania congressional plan was not, on the evidence before the Court, to be regarded as a partisan gerrymander, and four also asserted that, henceforth, partisan gerrymandering should be regarded as nonjusticiable. The four remaining Justices, who were in favor of further proceedings in the case, could not agree how to measure the severity of partisan gerrymandering or under what circumstances a plan was so egregious that it should be considered unconstitutional. The “swing” member on this case, Justice Kennedy, concurred on the merits of the decision finding the Pennsylvania congressional plan to be constitutional (asserting that the absence of agreed upon comprehensive and neutral principles for evaluation made it impossible to reach a judgment that the plan was unconstitutional), but opposed overturning Bandemer’s holding that partisan gerrymandering was justiciable, in the hope that sometime in the future there might arise a clearly manageable standard that the Court could adopt.
In Spring 2006, the Supreme Court heard LULAC v. Perry,3 where it addressed, among other things, the legal claim that the 2003 re-redistricting of congressional lines in the State of Texas is an unconstitutional partisan gerrymander.4 The Court majority rejected two types of partisan gerrymandering claims: (1) that mid-decennial reredistricting is inherently unconstitutional, and (2) that redistricting done for no motive other than partisan gain is inherently unconstitutional. Even the combination of a mid-decadal re-redistricting and the absence of motivation other than partisan gain were held not to present a constitutional issue.5 However, though the 2003 Texas congressional plan was not found to be an unconstitutional partisan gerrymander, five members of the Court reiterated the holding in Vieth that partisan gerrymandering can, in principle, be recognized as a violation of equal protection, and two others (Chief Justices Roberts and Justice Alito) took no position on that question.6
Although, “as in Vieth,” there existed “no majority for any single criterion of impermissible gerrymander”7, this case marks a potential sea change in how the Supreme Court adjudicates partisan gerrymandering claims. For the first time, a criterion for detecting and measuring gerrymandering – known as partisan symmetry – attracted considerable positive attention by the justices. The potential importance of the partisan symmetry criterion was argued for by us and two of our colleagues in an Amicus Brief submitted in that case (on behalf of neither party).8 The ideas in that Amicus Brief were discussed in three of the opinions, including the plurality opinion written by Justice Kennedy.9 A majority of Justices now appear to endorse our view that the measurement of partisan symmetry can be used as part of a broader test in resolving partisan gerrymandering claims. This case marks the first time that a majority of the Court has agreed on the potential use of any criterion for measuring the effects of partisan gerrymandering. (This of course merely recognizes current practice in many lower courts where the vast majority of experts routinely compute and often present results on the partisan fairness of redistricting plans based on the concept and measures of partisan symmetry we describe here.)
Two Justices (Stevens and Breyer) see it as “a helpful (though certainly not talismanic) tool.”10 Speaking for himself alone, Justice Stevens identifies departure from partisan symmetry as one of eight criteria he would make use of in determining effects-based violations of equal protection in the context of partisan gerrymandering claims,11 and he explicitly finds that the challenged plan violates a partisan symmetry test.12 Moreover, Justice Stevens asserts that the “symmetry standard … is undoubtedly ‘a reliable standard’ for measuring a ‘burden .. on the complainants’ representational rights’.”13
Two Justices (Souter and Ginsburg) look to the future and indicate that they “do not rule out the utility of a criterion of symmetry as a test.”14 And most importantly, they explain that “interest in exploring this notion is evident [on the Court].”15
A fifth Justice, Justice Kennedy, also does not rule out use of this criterion, adding two caveats: that “asymmetry alone is not a reliable measure of unconstitutional partisanship” and that the Court may need to administer the standard retrospectively rather than prospectively.16 Justice Stevens characterizes Justice Kennedy’s view as one of “leaving the door open to the use of the standard in future cases.”17
Furthermore, two additional justices, Chief Justice Roberts, joined by Justice Alito, while asserting that appellants have not yet provided “a reliable standard for identifying unconstitutional gerrymanders”18 leave open the question of an appropriate standard.19
We find the openness of a majority of the Justices to making use of measures of partisan bias (a deviation from partisan symmetry) as part of a standard for unconstitutional partisan gerrymandering to be an extremely promising development for reigning in abuses of gerrymandering in American democracy20. We use this essay to respond to the suggestion of Justices Souter and Breyer that “further attention … be devoted to the administrability of such a criterion at all levels of redistricting and its review.”21 In the process of so doing we comment on the three specific new ideas raised by Justice Kennedy’s discussion in LULAC of possible tests for partisan gerrymandering: his suggestion that a “challenge could be litigated if and when the feared inequity arose” rather than on the basis of “unfair results that would occur in a hypothetical state of affairs;”22 his suggestion that we need to look comparatively to judge relative magnitudes of partisan bias in alternative plans (an idea which parallels how courts have investigated ill-compactness claims based on state constitutional challenges), and his specific suggestion to distinguish the case where a majority party has its voting strength exaggerated (which is how he characterizes the 2003 plan, based on the actual results in 2004, with the Republicans as the majority party) from the case where a party that is in the process of becoming a minority in terms of voting support uses redistricting to entrench itself in power over the remainder of the decade (which is how he characterizes the 1991 Texas congressional plan, with the Democrats seen as a once dominant party which loses voter support over the course of the decade).23
We also address the concerns of Justice Kennedy and other Justices that a partisan symmetry test can only be effectively used if there is a specified threshold to distinguish unconstitutional gerrymandering from mere politics as usual.24 But we share the view of Justice Stevens that, even if the Court fully adopts the concept of partisan symmetry as one that is legally relevant, and recognizes the potential usefulness of the specific methodology that can be used to measure levels of partisan bias that we discuss below and in our previous writings, it is for the Court to make the critical judgments about what would constitute unconstitutionality or legally actionable thresholds and standards: “Justice Kennedy faults proponents of the symmetry standard for ‘not providing a standard for deciding how much partisan bias is too much’ (ante at 13). But it is this Court, not proponents of the symmetry standard, that has the judicial obligation to answer the question of how much unfairness is too much.”25 Although we believe that the choice of legally actionable thresholds for violations of partisan symmetry is the Court’s purview, social scientists can be helpful by clarifying the logical possibilities -- which we also do here.
The remainder of this essay consists of four parts: In Section II we expand and clarify the arguments laid out in King et al. (2005) as to the potential usefulness of the measurement of partisan symmetry, and we identify and rebut a number of common misconceptions about the partisan symmetry standard, most of which are given airing in various of the briefs filed in LULAC. Then, in Section III, we consider ways in which courts might address the issue of setting a prima facie legal threshold for when the level of partisan gerrymandering rises to a matter of legal concern -- so as to distinguish egregious and unconstitutional gerrymandering from politics as usual. Next, in Section IV, we consider how partisan symmetry can be made a component of a broader multi-criteria standard for partisan gerrymandering that deals with both overall equal protection and matters specific to particular districts.26 Finally, in Section V, we provide a concluding discussion that looks to the future of partisan gerrymandering claims.