The Supreme Court is allergic to math

The Supreme Court does not compute. Or at least some of its members would rather not. The justices, the most powerful jurists in the land, seem to have a reluctance — even an allergy — to taking math and statistics seriously.

For decades, the court has struggled with quantitative evidence of all kinds in a wide variety of cases. Sometimes justices ignore this evidence. Sometimes they misinterpret it. And sometimes they cast it aside in order to hold on to more traditional legal arguments. (And, yes, sometimes they also listen to the numbers.) Yet the world itself is becoming more computationally driven, and some of those computations will need to be adjudicated before long. Some major artificial intelligence case will likely come across the court’s desk in the next decade, for example. By voicing an unwillingness to engage with data-driven empiricism, justices — and thus the court — are at risk of making decisions without fully grappling with the evidence.

This problem was on full display earlier this month, when the Supreme Court heard arguments in Gill v. Whitford, a case that will determine the future of partisan gerrymandering — and the contours of American democracy along with it. As my colleague Galen Druke has reported, the case hinges on math: Is there a way to measure a map’s partisan bias and to create a standard for when a gerrymandered map infringes on voters’ rights?

The metric at the heart of the Wisconsin case is called the efficiency gap. To calculate it, you take the difference between each party’s “wasted” votes — votes for losing candidates and votes for winning candidates beyond what the candidate needed to win — and divide that by the total number of votes cast. It’s mathematical, yes, but quite simple, and aims to measure the extent of partisan gerrymandering.

Four of the eight justices who regularly speak during oral arguments¹ voiced anxiety about using calculations to answer questions about bias and partisanship. Some said the math was unwieldy, complicated, and newfangled. One justice called it “baloney” and argued that the difficulty the public would have in understanding the test would ultimately erode the legitimacy of the court.