The Supreme Court announced Friday that it would, once again, consider whether partisan gerrymandering can be so extreme that it violates the Constitution.

The move comes after a term in which the justices had looked poised to impose some limits on partisan influence in redistricting, but ultimately seemed unable to agree on a workable standard for evaluating when state lawmakers cross a constitutional line.

The Supreme Court has invalidated racial gerrymanders in the past, but it has never struck down districts for being too partisan. The gerrymandering cases from last June—one from Maryland, the other from Wisconsin—were two of the term’s most anticipated decisions because they raised the possibility that the Court would do so for the first time. Early in the term, Justice Ginsburg herself described Gill v. Whitford, the Wisconsin case, as “perhaps the most important grant so far.”

But the decisions turned out to be anticlimactic: the Court found technical problems with both lawsuits and sent them back to the trial courts to be reevaluated. The justices also vacated a similar ruling against North Carolina’s congressional districts, returning the matter to the lower courts for reconsideration as well.

After reconsidering, the lower courts in Maryland and North Carolina struck down both states’ congressional maps. On Friday, the Supreme Court agreed to hear oral argument in appeals of both rulings. Under 28 U.S.C. § 1253 and 28 U.S.C. § 2284, the Supreme Court has mandatory jurisdiction in gerrymandering lawsuits, and so its decision to hear these cases does not suggest the justices are eager to revisit the issue. The only other options the Court had were to summarily affirm or reverse the judgments, neither of which was likely in light of the novelty and potential impact of the litigation.

The Maryland case, Lamone v. Benisek, No. 18-726, is the same one that the Supreme Court left unresolved last June. Republican voters allege that the Democratic legislature contorted the state’s 6th congressional district to incorporate more of the Washington, D.C. metro area, ensuring that the district’s longtime G.O.P. representative, Roscoe Bartlett, would lose re-election. (After 20 years in Congress, Bartlett was easily defeated in 2012, the first election conducted under the new map.) When the Court heard this case last term, it ruled unanimously that the plaintiffs were not entitled to immediate relief because they had waited too long to file suit.

In the North Carolina case, Rucho v. Common Cause, No. 18-422, Democratic voters claim that the state’s Republican-drawn congressional map is constitutionally infirm for three reasons.

  1. It intentionally dilutes Democratic votes either by “packing” them into blue districts or “cracking” them among red districts. In the course of denying accusations that the map was racially discriminatory, Republican lawmakers declared that their main motivation was to help Republicans win more seats.
  2. It exhibits a large and durable partisan asymmetry. In 2016, Republicans won 53 percent of the statewide congressional vote, which won them 10 of 13 seats. Depending on the eventual outcome in the state’s 9th congressional district, Republicans will have won 9 or 10 seats in the 2018 midterm elections while getting 50.3% of the statewide vote.
  3. It cannot justify its partisan asymmetry on legitimate grounds, like geography or compliance with the Voting Rights Act.

The arguments are mostly identical to last year’s, and can be read about more deeply in the parties’ briefs. But unlike last year, the air at the Center for American Progress is heavy with dread, not anticipation.

The plaintiffs know that their window of opportunity has passed.

In Vieth v. Jubelirera 2004 challenge to a gerrymander in Pennsylvania, Justice Kennedy invited future litigants to present the Court with a workable standard for discerning an illegal partisan gerrymander. Liberal public policy organizations were hoping that, 13 years later, they had finally found the elusive standard that Kennedy had been searching for: the efficiency gap. A simple way of measuring wasted votes, the efficiency gap was proposed by Eric McGhee and Nicholas Stephanopoulos—two prominent political scientists—and described by Stephanopoulos as so:

The efficiency gap is simply the difference between the parties’ respective wasted votes in an election, divided by the total number of votes cast. Wasted votes are ballots that don’t contribute to victory for candidates, and they come in two forms: lost votes cast for candidates who are defeated, and surplus votes cast for winning candidates but in excess of what they needed to prevail. When a party gerrymanders a state, it tries to maximize the wasted votes for the opposing party while minimizing its own, thus producing a large efficiency gap. In a state with perfect partisan symmetry, both parties would have the same number of wasted votes.

But Justice Kennedy was apparently not ready to embrace this metric, and none of the other conservatives thought much of it at all. At oral argument, Chief Justice John Roberts said that the Wisconsin plaintiffs’ arguments struck him as “sociological gobbledygook.”

As oral arguments in these new cases approach, we’ll start seeing tweets and thinkpieces about how the Court is “allergic to math,” or, even more patronizing, that “math is hard” for the justices.

While the efficiency gap may seem like a clever way of judging a map’s bias, it compresses complex and variable human geography to a single number, and in the process is forced to distort and oversimplify. But even if the efficiency gap were more reliable, it is, at bottom, a pet academic theory: McGhee and Stephanopoulos suggest that an efficiency gap of two or more congressional seats, or 8 percent of state legislative seats, is a constitutional violation. It’s not anti-intellectual or anti-math to doubt whether these statistical cutoffs should be enshrined as constitutional law by the Supreme Court. 

In any event, unless Justice Kavanaugh’s views on redistricting are unexpectedly of a piece with the Brennan Center’s, it seems like the efficiency gap will have to content itself with being a clever idea.

So what then will the innumerate justices do with this case?

They could maximize their future jurisprudential freedom by holding that that no workable standard has been discovered. That would leave us where we’ve always been. But the Court could go further, and conclude that gerrymandering cases present a nonjusticiable political question, as Justices Rehnquist, O’Connor, Scalia and Thomas argued 14 years ago in Vieth. If the justices were to so decide, partisan gerrymandering claims would be all but locked out of federal court.

Finally, if the Court is inclined to once again sidestep the question, it could probably find a way to rule that, because the current maps have to be redrawn in 2020 anyway, these cases are likely to become moot and should not be decided.

And then we’d get the pleasure of going through all this again in 2021 and 2022.