Here is a guest post from Professor Peter Schuck:

Still in the Thickest Thicket

Peter Schuck

Just before Thanksgiving, a 3-judge federal court gave Democrats good reason to cheer. It struck down a Wisconsin districting plan favoring Republican candidates as an unconstitutional partisan gerrymander. This decision could be far-reaching because almost all states draw district lines to advantage their majority party in legislative and congressional elections. (Putatively non-partisan commissions draw the lines in a few states). The Supreme Court is hearing other gerrymandering cases and will surely review this one.  This is a judicial minefield; skepticism is warranted.

Legislated maps are almost inevitably partisan due to political, legal, and practical factors. Voters’ tend to reside in partisan clusters (Democrats in cities, Republicans in suburban and rural areas). Also limiting the mapping options somewhat is the Court’s one-person, one-vote rulings: districts must be roughly equal in population and reasonably compact except when necessary to protect minority voting rights. At the same time, the Court reads the Voting Rights Act to require districts to be “packed” with enough minorities to assure victory for a minority candidate, and this number must be large since many minorities are non-citizens and don’t vote. (Another constraint: California and some other states reject maps that divide “communities of interest.”)

But the Supreme Court has strongly resisted regulating partisan gerrymandering for federal elections. (Some states now constrain the gerrymandering of statehouse seats). No Court majority has endorsed a test for when maps are so egregiously partisan as to unconstitutionally disadvantage the other party. Indeed, no one opinion on this subject has even garnered a majority of justices! Court pluralities have rejected tests focused on legislators’ intent; partisanship is in legislators’ job description, and parsing their mixed motives is difficult. Other tests using multiple factors and hard-to-measure criteria would produce too much uncertainty and judicial discretion. Any constitutional test must be “judicially manageable,” the justices agree, but they have been unable or unwilling to come up with a satisfactory one.

Now comes the bold Wisconsin decision. Carefully reviewing these Supreme Court opinions and political scientists’ views about partisan gerrymandering, the judges adopted a test based on how many votes for each party a given map “wastes.” The Wisconsin Republicans sought to waste Democratic votes in two familiar ways: they “cracked” Democratic voters by placing them in districts where they would be too few to elect the Democrat, and “packed” them into districts where they would elect the Democrat by far more votes than needed. Both techniques gave Democratic votes little or no marginal effect on those election outcomes. They made Republican votes more “efficient” than Democratic ones, converting GOP votes into legislative seats at a higher rate, producing an “efficiency gap” between the parties larger than the average gap in past elections.  Unless Republicans could show that legitimate, non-partisan reasons required this particular map, it was unconstitutional.

This “efficiency gap” test for partisan gerrymanders is plausible; indeed, some election law scholars and state courts have endorsed it.  Even so, the Supreme Court should proceed with caution, skeptical of any such simple, “one-size-fits-all” solution. Here’s why.  Increased clustering of partisans in discrete communities would assure many wasted votes even with no packing.  Also, the test’s outcome can turn on slight changes in the distribution of votes among districts. It would also protect bipartisan gerrymanders protecting both parties’ incumbents from competition; they tend to have low efficiency gaps. The efficiency gap test, moreover, cannot easily account for how independent voters, third-party voters, and party-switching might make past voting a less reliable guide to predicting future efficiency gaps. And it makes much turn on precisely how large a gap courts will tolerate in deciding when waste becomes excessive and thus unconstitutional. More fundamentally, the wasted-vote measure misconceives how actual representation works. Even with a comfortable victory margin, a representative must still attend to the concerns of the other party’s voters, at least if she expects to seek re-election in a dynamic political environment. Indeed, if her party gerrymanders for vote efficiency, it will want to keep her victory margin low so that it can distribute its voters to win other districts.

Even more important, any such test will necessarily draw federal courts into new partisan battles from which they have heretofore been protected by the Supreme Court’s hands-off treatment of these gerrymanders. Using this test to regulate elections will be especially problematic because one can usually predict which party will benefit from it. (Indeed, its predictability is a supposed virtue). At a time when our public institutions are experiencing a crisis of legitimacy, when public esteem for even the Court has declined, and when the next round of appointments to it will be bitterly contested, we can ill afford its further politicization.  Alas, partisan gerrymanders may be one of those problems without any good judicial solution.

Peter H. Schuck is the Simeon E. Baldwin Professor Emeritus of Law at Yale.  His most recent books are Why Government Fails So Often, and How It Can Do Better (Princeton, 2014), and  One Nation Undecided: Clear Thinking About Five Hard Issues That Divide Us (Princeton, Feb. 2017)