A better way to fix gerrymandering: math

A better way to fix gerrymandering: math
© Greg Nash

Americans across party lines strongly disapprove of gerrymandering, and rightly so. Gerrymandering undermines the foundational principle underlying the American system of district-based representation: namely, that voters within a constituency should share local perspectives and live reasonably near one another. When the Supreme Court recently held that the judiciary has no authority to curtail gerrymandering, many would-be reformers were disappointed. 

They shouldn’t be. The court’s decision provides an opportunity to turn away from failing gerrymandering reform strategies, and toward a better way.

A typical person on the street can sense, merely by looking at a map, whether gerrymandering is out of control. It’s visually obvious when the shapes of legislative districts have been warped and twisted in improbable fashion. Preventing this requires limiting the discretion of political mapmakers to distort district shapes beyond the limits of common sense.


Unfortunately, a misguided focus on litigating gerrymandering’s political effects has diverted potentially useful reforms for the past several years. Gerrymandering reform is too often approached as a mechanism for the redistribution of political power, and calls for judicial intervention are too often attempts to “win” the redistricting process. But, as Chief Justice John Roberts correctly wrote in the Supreme Court’s recent decision, nothing provides “a solid grounding for judges to take the extraordinary step of reallocating power and influence between political parties.”

The political approach to gerrymandering reform was misguided for several reasons. First, the Constitution protects individual voting rights, but it offers no similar protections for combinations of interests, and especially not for political parties, which many founders abhorred. Moreover, gerrymandering can occur for a wide variety of reasons — not only for partisan advantage, but also for reasons such as protecting powerful incumbents or demographic minorities. And of course, framing reform in partisan terms only increases resistance to it, as well as drawing the courts into political battles where they do not belong.

Worst of all, approaching gerrymandering reform as a political balancing act does nothing to address the evils most Americans find in the practice. This is because gerrymandering to the benefit of one party in one place would become acceptable as long as it was balanced by gerrymandering to favor another party elsewhere. This flawed approach risks creating more gerrymandering rather than less, as well as doing nothing to mitigate ideological polarization, make general elections more competitive, or make elected officials more responsive to the average voter. 

Gerrymandering can and should be constrained, but we need to get the focus off of political engineering and back onto simple good governance. The Constitution provides the process for doing so, through its Elections Clause specifying that Congress can “make or alter” the rules for congressional elections. Congress has used this authority many times in the past to require compactness in congressional districting, and could easily do so again.

Constraining the irregularity of district shapes is no more difficult than the simplest mathematics. All that is necessary is for legislators to enact a limit on how long a district’s perimeter can be relative to its area (with adjustments for the portion of the boundary over which mapmakers have no control). This would by itself eliminate all the worst instances of gerrymandering in one fell swoop. A forthcoming study I have authored for the Mercatus Center at George Mason University explores specific methods for doing exactly that, including options that would invalidate roughly 5-8 percent of current congressional districts depending on the standard adopted by lawmakers, with the effects of reform concentrated on the most gerrymandered states.

Such an approach would be far superior to nebulous determinations of political motivations or advantage, or which introduce subjective and controversial value judgments. Instead of parsing the perceived motivations or effects of gerrymandering, it would directly limit the gerrymandering itself — and in a way that is simple, clear, national, and neutral.

The national discussion of gerrymandering has been so dominated of late by political framing that it will take a major attitude adjustment for many reform advocates to approach the problem in a fresh way. But reform won’t happen if reformers are simply seeking to replace one form of political engineering with another. Durable and broadly accepted reforms will only be adopted if we refocus the discussion on the foundational purpose of legislative districting — that voters within the same constituency are those who live near to one another.

Charles Blahous is the J. Fish and Lillian F. Smith Chair and senior research strategist at the Mercatus Center at George Mason University; he specializes in domestic economic policy. Blahous served as Deputy Assistant to the President for Economic Policy and Deputy Director of the White House National Economic Council during the George W. Bush administration. From 2010 through 2015, he served as public trustee for Social Security and Medicare. He is author of Social Security: The Unfinished Work and Pension Wise: Confronting Employer Pension Underfunding — and Sparing Taxpayers The Next Bailout.