Many students choose law school after getting their freshman math grades, and law-school curricula make little attempt to build numeracy among these refugees. Because complex issues inevitably involve statistical information, that gap in legal education can cause mischief, especially when it affects judges.
For example, it may explain the Supreme Court’s rather puzzling revisit to the political gerrymandering question this Wednesday, in a case called Benisek v. Lamone.
Begin with last October’s oral argument in Gill v. Whitford, the political-gerrymandering case many observers expected to be the Court’s major statement on the issue. The challengers to Wisconsin’s Republican-leaning system of legislative districts claimed that it violated both the First Amendment (by “penalizing … voters because of their political beliefs”) and the Equal Protection Clause of the Fourteenth Amendment (by “diluting the political influence of a targeted group of voters”). They asked the Court to ratify the lower court’s three-part test. Under that test, a legislative map is invalid if it (1) is intended to discriminate among voters based on partisan identity; (2) causes a “large and durable” political swing in representation from one party to another; and (3) lacks any other reason or justification except political advantage.
The challengers offered the Court a number of ways to measure the “large and durable” aspect of a partisan swing; most prominent was the so-called “efficiency gap.” The “EG” was developed by Eric McGhee, a political-science fellow at the University of California at Berkeley; the lower court in Gill defined it as “a figure that represents the difference between the parties’ ‘wasted votes’ in an election. A vote is ‘wasted’ under this analysis if it is either (1) cast for a candidate who lost the election or (2) cast for the winning candidate, but in excess of what the candidate needed to win. The efficiency gap for a particular election is the difference between the parties’ total wasted votes among all of the districts, divided by the total number of votes cast.” Thus, if voters of Party A are crowded into districts where their candidates win by 60 to 40 percent, while voters of Party B predominate in districts where their candidates win by 51 to 49 percent, the EG suggests a skew against Party A measured by the excessive margins in their “safe” seats versus the narrower margins in the other party’s seats.
There are valid reasons to question the usefulness of the EG and other statistical tests of the balance of a legislative plan. Here’s an invalid one, though, offered at oral argument by Chief Justice John Roberts: “you’re taking these issues away from democracy and you’re throwing them into the courts pursuant to, and it may be simply my educational background, but I can only describe as sociological gobbledygook.”
It’s a perfectly respectable statistical theory, whether Roberts buys it or not; with a modicum of effort, even a J.D. could understand it.
So Wednesday’s case, which is a challenge to a Democratic gerrymander rather than a Republican one, may be on the docket because it offers—for good or ill—a chance for the justices to come out against gerrymandering without messing with numbers. That’s just one theory, but most observers agree that the Court’s treatment of the case is puzzling. Gill was argued on October 3. The papers for the Benisek appeal began to arrive at the Court four weeks later. The normal thing would have been to hold Benisek until Gill was decided; instead, on January 24, the Court accepted Benisek for oral argument this term, after Gill had been voted on in conference (we don’t know the result of that vote, presumably because opinions are still being written and circulated).
Benisek concerns the Sixth Congressional District of Maryland, which in its current form snakes across the flat top of the Old Line State, from the affluent suburbs of Washington in the east to rural Garrett County, closer to Pittsburgh than to Annapolis, in the west.
From 1992 to 2012, the Sixth District returned a Republican member of the House, Representative Roscoe Bartlett. In 2011, however, the Democratic state legislature redrew the district, producing a different partisan-registration balance, and Bartlett went down in defeat in 2012. The District is now represented by Democratic Representative John Delaney.
Since then, a coalition of Republican voters has been challenging the 2011 redistricting as an unconstitutional gerrymander. They offer the Court a pure First Amendment test that might, to a arithmophobic judge’s eye, seem to offer advantages over the “efficiency gap” and related statistical tests. They explain in their brief:
Unlike the equal-protection approach to partisan gerrymandering, the First Amendment retaliation framework does not depend on a unifying definition of “fairness” or require courts to determine when a map has gone “too far.” It instead asks whether the State has imposed a real and practical burden (one that is more than de minimis) in retaliation for past political support for the opposition party. … As this Court’s ballot-access cases make clear, the inquiry is pragmatic and functional, turning not on statistical measures of imbalance, but on the practical effects of a gerrymander themselves.
The first issue in both these cases is whether the courts can even hear partisan gerrymandering cases at all. The hard-line conservative position is that, because there isn’t a clear and simple test, partisan legislative redistricting is and must be a function of bare-knuckle politics, without judicial review; thus it was at the framing, the argument runs, and thus ever mote it be. Justice Anthony Kennedy, the swing vote in cases like these, has refused to close that door, however. In a 2004 case called Vieth v. Jubilirer, he wrote that he hadn’t found a test that would work, but that one might come along.
These two cases put that possibility to the test. A conservative justice, or a swing justice, or a justice named, say, Kennedy, might prefer the Benisek test to that offered by the appellees in Gill. For one thing, the First Amendment is for Kennedy the Maslow’s Hammer of constitutional law: one size fits all. Kennedy may not enjoy regression analysis, but he can certainly count to “more than de minimis.” The Benisek appellants’ test, further, presents itself as a test of one district only, rather than as an attempt to overturn an entire district map.
Thus, adopting the Benisek test might, on the one hand, avoid a sweeping ruling that would upset an entire state’s map (one that has empowered a Republican supermajority in purple Wisconsin) while, on the other, not putting the courts out of the gerrymander business altogether (and rebuking a Democratic legislature in annoyingly blue Maryland). Perhaps most important, the “pragmatic and functional” test would remove the case from the disorienting Mathmagic Land of the EG, and place it in the realm of gut feelings, which is where Kennedy always feels most at home.
The Gill challengers recognize that the Benisek test, if adopted, would offer a dull knife instead of the scalpel they seek. They urge the Court to adopt their test and use it to find the Sixth District unconstitutional. Their test is superior, they argue: It “would not jeopardize the vast majority of congressional plans,” and would not “be skewed in either party’s favor.”
Whatever your underlying view, redistricting cases are hard. Formulating the classic “one person one vote” rule (which required only long division) apparently cost one justice both his sanity and his seat. The complications of partisan gerrymandering require statistics and probability, and the variables are, to use an overused term, exponentially more complex.
Deciding cases like this, though, is why judges make the big bucks. But that it’s hard doesn’t mean it can’t be done well. The worst possible result of these paired cases would be a green light to legislatures to cement themselves in power; almost as bad would be a rule judges may deploy when they feel like it, but that nobody really understands.