A Case for Math, Not ‘Gobbledygook,’ in Judging Partisan Voting Maps

The following article by Adam Liptak was posted on the New York Times website January 15, 2018:

Chief Justice John G. Roberts Jr. said that statistical evidence said to show that Wisconsin’s voting districts had been warped by political gerrymandering struck him as “sociological gobbledygook.” Credit T.J. Kirkpatrick for The New York Times

WASHINGTON — In October, when the Supreme Court heard argumentsin a case that could reshape American politics, Chief Justice John G. Roberts Jr. registered an objection. There was math in the case, he said, and it was complicated.

“It may be simply my educational background,” the chief justice said, presumably referring to his Harvard degrees in history and law. But he said that statistical evidence said to show that Wisconsin’s voting districts had been warped by political gerrymandering struck him as “sociological gobbledygook.”

Last week, Judge James A. Wynn Jr. came to the defense of math. “It makes no sense for courts to close their eyes to new scientific or statistical methods,” he wrote in a decision striking down North Carolina’s congressional map as an unconstitutional partisan gerrymander.

Judge Wynn directed his criticism to Republican state lawmakers, who had urged his three-judge Federal District Court to ignore what they called “a smorgasbord of alleged ‘social science’ theories,” and not to Chief Justice Roberts. But Judge Wynn did use one of Chief Justice Roberts’s most prominent opinions to make the point that numbers can have a role to play in judicial decision making.

That opinion, in Shelby County v. Holder in 2013, effectively struck down the heart of the Voting Rights Act of 1965. It included a statistical chart showing the shrinking “racial gap” between registration rates for black and white voters in six Southern states.

The statistics in the recent gerrymandering cases were more complicated, but not by much. Just as comparing registration rates between black and white voters yielded a “racial gap,” comparing the voting power of Republican and Democratic voters yields what the challengers in the Wisconsin case called an “efficiency gap.”

The efficiency gap is a measure of the consequences of the two basic ways of injecting partisan politics into drawing legislative maps: packing and cracking.

Packing a lot of Democrats into a single district, for instance, wastes every Democratic vote beyond the bare majority needed to elect a Democratic candidate. Cracking Democratic voters across districts in which Republicans have small majorities wastes all of the Democratic votes when the Republican candidate wins.

The difference between the two parties’ wasted votes, divided by the total number of votes cast, yields an efficiency gap.

At the argument of the Wisconsin case in October, Chief Justice Roberts mocked the efficiency gap, referring to it by its initials, and suggested that it was fiendishly complicated.

“The answer is going to be because E.G. was greater than 7 percent, where E.G. is the sigma of party X wasted votes minus the sigma of party Y wasted votes over the sigma of party X votes plus party Y votes,” he said. “And the intelligent man on the street is going to say that’s a bunch of baloney.”

Part of Chief Justice Roberts’s point was that a mathematical formula is not a legal standard, and that is true. In the early stages of the litigation, the challengers suggested that a gap of more than 7 percent was legally significant, which does seem arbitrary.

District Court panel in Wisconsin that struck down a state legislative map there did not base its decision on the efficiency gap, relying instead on a more conventional legal test that considered discriminatory intent, the map’s partisan effects and whether they were justified by other reasons. The efficiency gap, the court said, was evidence that corroborated the majority’s conclusions.

The same was true in the Shelby County opinion. Chief Justice Roberts did not contend that a particular racial gap proved a constitutional violation, but only that his numbers were good evidence of powerful changes. (This was probably just as well, as a recent ProPublica article suggested that there were flaws in the chief justice’s methodology.)

The Supreme Court has not hesitated to use social science to explore disparities between two groups. In 1954, in Brown v. Board of Education, for instance, the court cited studies from psychologists and others to show the negative effects of segregation in public schools.

On Friday, North Carolina lawmakers asked the Supreme Court to put Judge Wynn’s ruling on hold while the court considers two pending cases. In addition to the Wisconsin case, Gill v. Whitford, No. 16-1161, the court has also taken up one from Maryland, Benisek v. Lamone, No. 17-333.

One way or another, the Supreme Court is very likely to issue a landmark decision on political gerrymandering by June. Judge Wynn’s 190-page opinion surveyed many topics, but its most striking passages seemed addressed to justices who had majored in the humanities.

“The Constitution does not require the federal courts to act like Galileo’s Inquisition and enjoin consideration of new academic theories,” Judge Wynn wrote.

“That is not what the founding generation did when it adopted a Constitution grounded in the then-untested political theories of Locke, Montesquieu and Rousseau,” he wrote. “That is not what the Supreme Court did when it recognized that advances in our understanding of psychology had proven that separate could not be equal.”

View the post here.