Could Mathematics Save Us From Partisan Gerrymandering?
If the Democrats have a realistic chance of gaining back control of the government, one of the first battles it will have to win is the one against gerrymandering. Though cases about redistricting tend to go either in court, one Tufts University professor thinks she may have a winning solution: math.
Moon Duchin, a mathematics instructor with an expertise in geometry, spoke to the Chronicle of Higher Education about a summer class she devised specifically to prepare mathematicians to testify as experts in redistricting court cases.
Originally, Duchin thought she could be most useful collaborating with state redistricting committees to work out fair district lines. Then she realized that the powers that be often intentionally don’t want to create fair district lines, so her input would easily go ignored in the states that needed it the most.
Hence, she changed her focus to host a class to train mathematicians instead. The class isn’t so much about drilling students with her particular point of view on this subject, but assembling astounding mathematical minds to discuss this issue and work out potential math-backed solutions to the gerrymandering problem.
“When I started thinking about this, I was surprised to see that even though there were different mathematical attempts at a definition, you don’t ever see mathematicians testifying in court about it,” said Duchin.
After all, partisan powers are already using plenty of math to rig the system. Since each congressional district in the state has to be roughly equivalent in population size, politicians will find a way to draw the lines so that one particular party affiliation has the majority of voters in the majority of districts. It’s a complicated mathematical formula to ensure that one party gets the maximum number of representatives with the fewest number of votes.
When districts look like the examples above, it’s pretty obvious that legislators were trying to cram a particular demographic of people into a single district. However, courts have had trouble legally determining what a “compact” district should look like. That’s where geometry can enter the picture to demonstrate how compactness works from a mathematical perspective.
By Duchin’s own admission, one of the biggest challenges will be for geometry specialists to communicate the mathematical principles to those without degrees in mathematics. A professor could present a highly technical theory well amongst her peers, but that wouldn’t necessarily make it a winning argument for a jury or judge that can’t follow the logic.
To see which ideas people more easily grasp and which need further explanation, Duchin has been practicing discussing these concepts with various audiences (high school students, politicians, a public open forum, etc.) Developing the language to discuss the mathematics to a mixed crowd will be one of the class’ key focuses, and then the students can take that language to court.
“I don’t have any illusions that we’re going to settle that debate forever, but I think we can make a contribution to the debate,” said Duchin.
Duchin has good reason to think so, too. Last year’s federal court case Whitford v. Gill, set precedent by determining that the district lines in Wisconsin had been intentionally devised to benefit the Republican Party, and that legislators had no good reason for drawing their boundaries in that manner other than to manipulate that outcome. The plaintiff used a mathematical equation to demonstrate that this unfairness had occurred.
With any luck, the courts will continue to agree that mathematic principles are an unbiased way to judge the compactness of districts, thereby rejecting some of the inherent partisanship of allowing legislators to draw their own district lines.
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