The Art of the Rigged Map
Every ten years, a quiet process unfolds in state capitals across America that shapes the country’s political landscape more decisively than almost any election. Armed with census data, demographic projections, and increasingly sophisticated software, legislators redraw the boundaries of congressional and state legislative districts. The process is called redistricting, and in theory it is a neutral administrative exercise — an adjustment to reflect population shifts.
In practice, it is often something else entirely.
When North Carolina Republicans redrew their congressional map after the 2010 census, they used software that could analyze voting patterns block by block. The result was a map so deliberately skewed that in the 2012 elections, Democratic candidates received roughly 51 percent of the total congressional votes cast in the state — and won exactly four of thirteen seats. Republicans, with 49 percent of the vote, won nine seats. That’s not a glitch. That’s the system working as designed.
This is gerrymandering: the manipulation of electoral district boundaries to give one political party, racial group, or other faction a structural advantage that can persist for a decade or longer, regardless of how the actual electorate votes. It is a practice as old as the republic itself — the term dates to 1812, when Massachusetts Governor Elbridge Gerry signed a bill creating a contorted district shaped, according to a Boston newspaper cartoonist, like a salamander — and it has never been more dangerous or more technically precise than it is today.
How It Actually Works: Packing, Cracking, and the Geometry of Power
To understand gerrymandering, you need to understand two techniques that form its core toolkit: packing and cracking.
Packing means concentrating opposition voters into as few districts as possible. If you can cram 80 percent of your opponents’ reliable voters into a single district, they’ll win that district in a landslide — but they’ll have wasted enormous numbers of votes on an already-certain outcome. Meanwhile, your party wins every surrounding district with modest, efficient margins.
Cracking works in the opposite direction. Instead of concentrating opposition voters, you disperse them — slicing a community in half, or into thirds, and distributing those fragments across multiple districts where they will always constitute a minority. A city whose voters lean heavily toward one party might be carved into four wedge-shaped slices, each one attached to a vast rural hinterland that reliably votes the other way.
Used together, packing and cracking allow a party that controls the redistricting process to lock in durable majorities that simply don’t reflect the underlying preferences of the voting population. Political scientists measure this using a metric called the “efficiency gap,” developed by University of Chicago law professor Nicholas Stephanopoulos and election analyst Eric McGhee. The efficiency gap calculates the difference in “wasted votes” — votes cast for losing candidates, or surplus votes for winning candidates that exceeded what was necessary for victory — between the two parties. A large efficiency gap signals a deliberately skewed map.
Technology has turbocharged these techniques dramatically. Before computers, gerrymanderers worked with paper maps and intuition. Today, firms like REDMAP — a Republican redistricting initiative launched in 2010 — use software that can model millions of possible district configurations, stress-testing each one against historical voting data, demographic trends, and likely future population shifts. The Republican State Leadership Committee spent roughly $30 million on REDMAP, targeting state legislative races in key swing states in 2010. By winning those legislatures just before the post-census redistricting cycle, Republicans were able to draw maps in Pennsylvania, Ohio, Michigan, Wisconsin, and elsewhere that delivered durable congressional advantages throughout the entire 2010s.
Democrats have caught up. In 2021, they hired their own data scientists and used similar technology in states they controlled, including Illinois, where they drew maps that a federal court later described as having “diluted” Hispanic voting strength in certain areas — a reminder that gerrymandering is a bipartisan sin, even if Republicans have wielded it more systematically in recent cycles.
The Racial Dimension: When Lines Become Weapons Against Communities
Partisan gerrymandering and racial gerrymandering are legally distinct, but they are often deeply intertwined — and the racial variety carries constitutional and statutory consequences that the partisan variety, remarkably, does not.
The Voting Rights Act of 1965 prohibits drawing maps that dilute the voting power of racial minorities. Courts have struck down districts designed to prevent Black, Latino, or other minority voters from electing representatives of their choice. The Supreme Court’s ruling in Shaw v. Reno (1993) established that bizarrely shaped districts drawn primarily on racial grounds could violate the Equal Protection Clause of the Fourteenth Amendment.
Yet the line between racial and partisan gerrymandering is blurry in ways that are easily exploited. Because race and party affiliation are so strongly correlated in many American communities — Black voters, for example, vote Democratic at rates above 85 percent — a mapmaker can claim to be drawing partisan lines while functionally drawing racial ones. “We’re targeting Democrats, not Black voters,” goes the defense, even when the practical effect is the same.
The Supreme Court confronted this problem directly in Alabama Legislative Black Caucus v. Alabama (2015) and Cooper v. Harris (2017), finding that states had improperly packed Black voters into majority-minority districts under the guise of Voting Rights Act compliance. More recently, in Allen v. Milligan (2023), the Court surprised many observers by ruling 5-4 that Alabama’s congressional map likely violated the Voting Rights Act by failing to create a second district where Black voters had a realistic opportunity to elect a representative of their choice. Chief Justice John Roberts joined the Court’s liberals in that decision — a rare moment of judicial brake on what had seemed like an accelerating erosion of minority voting protections.
But the 2023 ruling in Alexander v. South Carolina State Conference of the NAACP swung the other way, with the Court making it harder for challengers to prove racial gerrymandering when the state claims its motivations were partisan. The standard of proof, the majority held, was extremely demanding — plaintiffs needed “direct evidence” of racial sorting or circumstantial evidence that was “so powerful that no other explanation is plausible.” Critics argued this effectively gave states a roadmap to launder racial gerrymandering as partisan gerrymandering and escape legal accountability.
The Supreme Court Slams the Door — Then Leaves It Open a Crack
The most consequential ruling in the modern gerrymandering saga came in 2019, when the Supreme Court issued its decision in Rucho v. Common Cause. The case involved extreme partisan gerrymanders in North Carolina (Republican) and Maryland (Democratic). Both maps were, by any reasonable analysis, designed to lock in durable partisan advantages. The plaintiffs argued this violated the Constitution.
In a 5-4 decision written by Chief Justice Roberts, the Court said that federal courts simply could not adjudicate partisan gerrymandering claims. Such claims, Roberts wrote, presented “political questions beyond the reach of federal courts.” They lacked “judicially manageable standards” — meaning there was no neutral, principled basis on which a judge could say one gerrymander was too extreme while another was acceptable.
The ruling was widely seen as a watershed moment. It didn’t say partisan gerrymandering was fine; it said federal courts were powerless to stop it. Justice Elena Kagan’s dissent was scathing. “The partisan gerrymanders in these cases deprived citizens of the most fundamental of their constitutional rights: the rights to participate equally in the political process, to join with others to advance political beliefs, and to choose their representatives,” she wrote. “For the first time ever, this Court refuses to remedy a constitutional violation because it thinks the task beyond judicial capabilities.”
Rucho did not, however, close all doors. It explicitly noted that state courts could still hear partisan gerrymandering claims under state constitutions. This set off a wave of state-level litigation.
In 2022, the North Carolina Supreme Court — at the time controlled by Democratic justices — struck down the Republican legislature’s congressional map as an unconstitutional partisan gerrymander under the state constitution. Republicans then won control of the state supreme court in the November 2022 elections, and in 2023 the newly constituted court reversed that decision, reinstating the original map. The whiplash illustrated precisely why relying on state courts to police gerrymandering is itself a fragile solution — the judges, in many states, are elected partisans.
The Supreme Court entered this drama again with Moore v. Harper (2023), in which the North Carolina legislature advanced the “independent state legislature theory,” arguing that state courts had no authority to review federal election laws, including congressional maps. In a relief to democratic norms advocates, the Court rejected the most extreme version of this theory 6-3 — but the case illustrated just how far some legislators are willing to go to insulate their maps from judicial review.
Why Reform Is So Difficult: The Foxes and the Henhouse
If gerrymandering is so widely recognized as a distortion of democratic representation, why hasn’t it been fixed? The answer lies in a fundamental conflict of interest that is almost comically obvious once you see it: the politicians who benefit most from gerrymandered maps are precisely the politicians who would have to vote to change the system.
Congressional Republicans who hold seats drawn to be structurally safe have no rational incentive to support a reform that would make their seats competitive. The same is true for Democrats in states they control. “Politicians have a natural interest in perpetuating the system that elected them,” notes Justin Levitt, a constitutional law professor at Loyola Law School and a former senior policy adviser at the Justice Department. “Asking them to voluntarily give up that advantage is asking them to act against their immediate self-interest.”
Congress could theoretically pass legislation requiring independent redistricting commissions for all congressional districts. The For the People Act, passed by the House of Representatives in 2021 with unanimous Democratic support, contained such a provision. It died in the Senate, blocked by a Republican filibuster. The Freedom to Vote Act, a scaled-back version, suffered the same fate.
Independent redistricting commissions — in which a panel of citizens, not legislators, draws the maps — have been adopted in about a dozen states, including California, Colorado, Michigan, and Arizona. The evidence suggests they produce meaningfully less skewed results. California’s commission, created by Proposition 11 in 2008 and expanded by Proposition 20 in 2010, has been studied extensively. A 2022 analysis by researchers at Princeton found that California’s congressional maps had among the lowest partisan bias scores in the nation.
But commissions are not a silver bullet. Members are selected through processes that can be gamed. Commissioners can be lobbied, misled, or simply guided by implicit biases. Iowa’s nonpartisan legislative services bureau draws some of the country’s least gerrymandered maps using a system that prohibits consideration of partisan data — but Iowa is a predominantly white, relatively homogeneous state where that approach is easier to implement. Applying it to a diverse, complex state like Texas or Georgia is a different challenge entirely.
Ballot initiatives have created commissions in several states, bypassing resistant legislatures. But initiatives are only available in 26 states, and many of the worst gerrymandering offenders — including Texas, Georgia, and North Carolina — lack the initiative process for constitutional changes.
The Stakes: What Gerrymandering Actually Costs Democracy
Beyond the horse-race politics, gerrymandering carries real costs for democratic governance. Safe seats — heavily partisan districts insulated from general election competition — tend to produce more extreme legislators, because the only meaningful electoral threat comes from a primary challenge from the ideological base.
Political scientists have long debated the degree to which partisan polarization is directly caused by gerrymandering versus other factors like geographic self-sorting (liberals clustering in cities, conservatives in rural areas). The evidence is mixed. Some studies find that legislators from safe seats are no more extreme in their voting records than those from competitive districts. Others find meaningful effects, particularly in state legislatures.
What is harder to dispute is the effect on accountability. A legislator who faces no realistic threat of losing in November has weakened incentives to be responsive to the median voter in their district. When roughly 95 percent of congressional districts are considered “safe” in any given election cycle — as has been the case in recent years — the competitive elections that are supposed to discipline politicians and translate public preferences into policy outcomes simply don’t exist for most Americans.
There is also the question of legitimacy. When millions of voters cast ballots and find that those ballots are structurally diluted before they are even counted, trust in democratic institutions erodes. A 2022 survey by the nonpartisan Pew Research Center found that 55 percent of Americans said they were not confident that elected officials reflected the needs and interests of people like them. Gerrymandering is not the only reason for that sentiment, but it is an architecturally designed reason.
The Path Forward: Technology, Courts, and the Long Game
The redistricting cycle following the 2020 census has produced maps that are already being contested in dozens of lawsuits. The 2030 cycle will bring another round. What will determine whether gerrymandering is finally constrained — or becomes even more entrenched?
Several forces are converging. Artificial intelligence is making mapmaking more precise, but it is also making gerrymandering more detectable. The same computational tools used to draw skewed maps can be used to analyze them, generating thousands of alternative maps to demonstrate that a legislature’s chosen boundaries are statistical outliers. Courts, including some state courts, have begun accepting this kind of algorithmic evidence.
Demographic change creates headwinds for some current gerrymanders. In Texas, where Republicans drew aggressive maps after 2020, the state’s rapid growth in Latino population means that current district configurations may not hold through the decade — the census data may simply shift the underlying demographics too quickly for the maps to hold.
And the legal landscape, while hostile at the federal level, remains active at the state level. Organizations like the National Redistricting Foundation, chaired by former Attorney General Eric Holder, are funding litigation and redistricting reform campaigns across multiple states simultaneously — a long-game strategy designed to create reform in enough states before the 2030 census to meaningfully alter the national picture.
“This is not a problem we’re going to solve in one cycle,” Holder has said. “It’s a generational effort.” That framing is probably correct — and probably insufficient to comfort the tens of millions of voters who live in districts where, for the next several years, their votes are already rendered structurally irrelevant by a map drawn in a closed room by the people it was designed to protect.
The salamander still lives. It has just learned to use a computer.