Gerrymandering Explained
Infographics, an analogy, what's going on in Texas, the origin of the weird name, and plenty of links to explore.
We’re used to seeing big numbers of voters from across the country all added up to a total “popular vote” – but that’s not how our electoral system actually works. Each of us goes to a local polling precinct where we vote for the people who represent us, from the national level (Congress and the Electoral College) all the way down to our neighborhood or district.
Districts don’t have the same number of voters from year to year, because young people turn 18 and become eligible, and some voters die or move away. So when new U.S. census data comes out, maps of voting districts need to be redrawn, a process known as “redistricting.” There are usually many different ways to draw those maps, but they should be drawn in a fair way that follows the principle of “one person, one vote” as closely as possible: If each district in a city elects their own councilperson, for example, it’s fair that each district has about the same population, so that each councilperson represents about the same number of people.
But fair voting districts aren’t just a matter of population. “Gerrymandering” describes the practice of arranging voters into districts in an unfair way that gets the map-makers the outcome they want, rather than the outcome that best represents what the voters want. This excellent infographic from Time Magazine shows how gerrymandering works in politics:
Resources to explore:
Redistricting Report Card | The Gerrymandering Project at Princeton University
The Partisan Advantage Tracker from Michigan State University’s Institute for Public Policy and Social Research, which compares fair representation (based on popular vote totals) to election outcomes
Districtr, a free browser-based tool for drawing districts and mapping your community from the Data and Democracy Lab at the Brooks School of Public Policy at Cornell University
What happened in Texas?
In June, the New York Times reported that the Trump administration was pressuring Texas lawmakers to gerrymander districts to produce more Republican seats, not at the usual time after a census but in the middle of the decade. The governor of Texas, Greg Abbott, convened the Texas legislature in a special 30-day session for redistricting. President Trump told CBS News that he expected the Texas maps to be redrawn in such a way that Republicans would gain five additional seats in the U.S. House of Representatives. A shift of five seats in Texas could mean the difference between Republicans retaining their slim majority in the 2026 midterm elections or not.
The map of voting districts passed by the state legislature in 2021 (the usual time for redistricting after a census) had been facing a legal challenge already. The Texas Tribune reported:
Though whites and Latinos made up nearly the same share of the population in Texas in 2020, the state drew 23 white-majority districts out of 38 total congressional districts, while Latino voters made up majorities in only seven. The remaining eight districts had no majority group. …If a court finds that to be true, it wouldn’t be the first time: in every decade since the Voting Rights Act was enacted in 1965, Texas has been found by a federal court to have violated federal law by illegally discriminating against voters of color.
In the 2025 special session, the Texas Senate passed a new map of voting districts, projected to add those five Republican seats to their Congressional delegation. ABC News reports that under the proposed new map, “Central Texas' 37th Congressional District, which is currently represented by Democrat Rep. Lloyd Doggett, will be consumed by four neighboring districts, three of which Republicans now hold.” Before the Texas House could vote on the map, Democrats in the chamber left the state for two weeks, preventing the quorum needed to hold a vote. The Texas Democrats returned on August 18, seeking unsuccessfully to amend the legislation, and the gerrymandered map was passed on party lines in the House on August 20 and the state Senate on August 22.
Other states may follow in Texas’ footsteps (Vice President J.D. Vance visited Indiana to exert pressure there, and Missouri’s lawmakers will consider a new gerrymandered map this week), and legal challenges are already beginning in Texas.
California’s governor, Gavin Newsom, proposed that as a retaliatory response to the new Texas maps, California would pass a new voting map that would gerrymander five additional seats for Democrats. In California, a nonpartisan commission is charged with producing voting maps, but the state legislature approved a special election in November to allow voters to choose whether to allow the gerrymander to proceed. Maryland’s governor, Wes Moore, indicated that he may pursue a more aggressive Democrat gerrymander, too.
An analogy
Gerrymandering is complicated. Let’s use a small-scale analogy to break it down.
A student council has big decisions to make this year, thanks to a big donation to the school. They will be able to choose between renovating the football field or the auditorium, where theater productions take place. So everyone’s paying lots of attention to the vote for student council members. Each council member is elected by a separate homeroom.
Will the homerooms choose a football player or a theater star to represent them? That depends on who’s in each homeroom. There’s a roughly equal number of football players and theater stars in the class, so the vote will be close.
Imagine if we let the football team’s captain choose who’s in each homeroom. They would want as many homerooms as possible to elect a football player to student council, right? That way they’d be sure to get a renovated field to play on. To achieve that, they might put most of the theater stars in a single homeroom, where they’ll only get to elect one theater-friendly student council rep. Then they’d spread out the football players among the remaining homerooms, where they can elect many student council reps who will outvote the theater-friendly rep.
But if the director of the student play were choosing who’s in each homeroom, they might do the opposite.
Neither of these homeroom plans is fair. A fair election would represent the reality: a tight race between two roughly equal groups.
We haven’t even mentioned the rest of the class, who don’t perform in the theater or play on the football team. Both the theater stars and the football players should have to convince those people that their plan for the money is the best for everyone: After all, everyone can enjoy a football game or a theater production.
What if we put someone else in charge of assigning homerooms? Say the student newspaper editor. They might put all the football players in one homeroom, all the theater stars in another, and everyone else in the remaining homerooms. Or they might spread everyone out evenly. In either case, the election will be more competitive, and the student council won’t be dominated by any one group. They will have to debate and discuss the best option.
Why is it called gerrymandering?
Elbridge Gerry might not be a household name now, but if you name a governing body at the time of the American Revolution and the signing of the Constitution, you can bet he was there. He even served as James Madison’s vice president, until he died in office.
In 1812, while he was governor of Massachusetts, the state adopted a new map of voting districts. The map gave an unfair advantage to the Democratic-Republicans, Elbridge’s party, and Gerry signed it into law. The opposing party, the Federalists, objected — you could tell that the Democratic-Republicans were acting in bad faith, they argued, because of the bizarre shapes of the districts they drew. One, in Essex County, even looked like a dragon — or a salamander. Someone (no one knows who) joked that it should be called the “Gerry-mander,” after Gerry. Artist Elkanah Tisdale, working for the Boston Gazette, was inspired to draw a cartoon of the mythical animal, and the “Gerry-mander” appeared in print for the first time. (Check out this image of the newspaper from the Massachusetts Historical Society.)
A short history of Gerrymanders
The monstrous “Gerry-mander” has since been a regular feature in American history and politics. In 1961, a man from Memphis, Tennessee, Charles Baker, brought his case against gerrymandering all the way to the Supreme Court, arguing that his vote effectively counted less than that of Democrats living in rural areas of the same county, a violation of the 14th Amendment. Baker won his case, leading to the Supreme Court ruling that each person’s vote should have equal weight to any other’s — the “one person, one vote” principle.
Computers and algorithms have made it possible to create much more complicated gerrymandering schemes in the 21st century. Leading up to the 2010 census, the Republican State Leadership Committee announced a plan called REDMAP (REDistricting Majority Project) to win majorities in state legislatures and then to gerrymander the states with Republican majorities, so that they’d be able to win a majority of seats in the House of Representatives. Strategist Karl Rove described the strategy to the Wall Street Journal. The plan worked: In 2012, Republican candidates for the House of Representatives lost the election to Democrats by more than 1 million votes, but still ended up with the majority by 33 seats, as a result of REDMAP.
Voting rights organizations filed lawsuits in four states, and the Wisconsin case, Gill v. Whitford, came before the Supreme Court in 2017. But this time the Supreme Court ruled that it didn’t actually have the authority to make decisions about electoral maps at all, because they were a question of politics rather than law, and some justices weren’t persuaded that individual voters’ rights had really been violated. However, some state Supreme Courts, relying on language in those states’ constitutions, struck down unfair maps and required that new, fairer ones be drawn.
The 2020 census led to another round of redistricting, and many of the new maps were also gerrymandered, some by Republicans and some by Democrats (in Illinois, for example). The Brennan Center compared each new map to fair, non-gerrymandered alternatives. They estimated that gerrymanders had given Democrats an unfair advantage in 7 districts, and Republicans an unfair advantage in 23 districts nationwide.
Some members of Congress have been trying to prohibit gerrymandering by law on the federal level. The Freedom to Vote Act, renamed the John R. Lewis Act, is a bill that was proposed several times in Congress (most recently in 2023), but has not been voted on in the Senate, due to Republican obstruction. Among many other reforms, it includes rules for fair redistricting and mandated that each state carry out redistricting in a transparent way with opportunities for public comment.
According to election law scholar Doug Spencer’s site “All About Redistricting,” “As of July 22, 2025, there are live litigation challenges to lines in 13 states.”
Sources:
“How Computers Turned Gerrymandering Into a Science” | By Jordan Ellenberg for the New York Times, Oct. 6, 2017
“How did we get all this gerrymandering? A short history of the Republican redistricting scheme” | by David Daley for The Guardian, 9 Aug 2025
(video) “Supreme Court to hear case testing the limits of partisan gerrymandering” | by Sam Weber and Laura Fong for PBS NewsHour, Oct 1, 2017
Ideas for solutions to gerrymandering:
“Geometry Solves Gerrymandering” | by Harvard economics professor Ronald Fryer for the New York Times opinion section, Aug. 12, 2025 - describing a redistricting fairness test he and his team developed, called the “Relative Proximity Index”
“The easiest way to end district gerrymandering? Eliminating districts” | by Matthew Algeo for The Washington Post, August 20, 2025.
How to end the forever redistricting wars, | by Ansley Skipper and Drew Penrose for If You Can Keep It on Substack, August 08, 2025
Single transferable vote systems described in The Future is Proportional: Improving Minority Representation through New Electoral Systems |
By Gerdus Benadè, Ruth Buck, Moon Duchin, Dara Gold, and Thomas Weighill
Who made my state’s map?
Short answer: It depends on the state. Look yours up at this link!
In some states, the state legislature draws the maps, and those are usually the gerrymandered ones. Think about it: If you have a seat in the state legislature, you want to keep it, or make sure someone else who shares your views keeps it. To avoid this kind of unfairness, ten states have chosen instead to appoint independent commissions for redistricting, so they can be (hopefully) more objective. Some of these commissions are required to have an equal bipartisan balance of Republicans and Democrats, to make them more fair.
To find out what’s going on in your own state, we recommend following:
Your local newspaper
Voting rights organizations in your state (which may need your support!)
All About Redistricting, a site run by an election law scholar
Read more:
“Who Controlled Redistricting in Every State” | by Chris Leaverton for the Brennan Center, October 5, 2022
“As Democrats fight ‘fire with fire,’ gerrymandering opponents seek a path forward” | by Jonathan Shorman for the Missouri Independent, August 22, 2025
“Partisan Gerrymandering and the Efficiency Gap” | by Nicholas Stephanopoulos and Eric McGhee, University of Chicago Law Review, October 1, 2014
Redistricting news on Democracy Docket
Redistricting news on Fairvote.org