The One-Sentence Version

Gerrymandering has existed since 1812, but the modern crisis began in 2010 when the Republican State Leadership Committee spent $30 million on a project called REDMAP to win state legislatures in the census year, seize control of redistricting, and build a structural advantage that allowed Republicans to keep the House majority in 2012 despite receiving 1.4 million fewer votes than Democrats.


By the Numbers

WhatNumberSource
Year the word “gerrymander” was coined1812[12]
Money spent on REDMAP~$30 million[2][3]
State legislative seats Republicans gained in 2010~700[2]
State legislative chambers that flipped to Republican20[2]
More votes Democrats won in 2012 House races1.4 million[1][2]
House seats Republicans held despite losing the popular vote (2012)234 to 201[1]
Times Ohio Supreme Court struck down gerrymandered maps7[8]
Competitive House seats in 2024 (out of 435)~69[4]
Districts Republicans controlled in post-2020 redistricting177[4]
Districts Democrats controlled in post-2020 redistricting49[4]
States where voters approved redistricting reform with 60%+6+[4]

Where the Word Comes From

In 1812, Massachusetts Governor Elbridge Gerry signed a bill redistricting the state to benefit his party. When mapped, one of the twisted districts north of Boston resembled a salamander. An editor at the Boston Gazette reportedly said: “Salamander! Call it a Gerrymander.”[12]

The political cartoon spread rapidly, and the word entered the American vocabulary. The irony: Gerry himself disliked the practice but signed the bill anyway. His party won 29 seats to 11, but Gerry lost his own reelection.[12]

Both parties have been doing it ever since. Virginia, North Carolina, and South Carolina drew manipulated districts in the late 18th century. Between 1872 and 1896, at least one state redrew its boundaries every single year. This was bipartisan misbehavior from the start.[12]


What Changed: Computers and Data

For most of American history, gerrymandering was a crude art. Mapmakers drew lines by hand with limited data. The results were imprecise.

Three developments changed that:

  1. The 1960s: The Supreme Court’s “one person, one vote” decisions mandated redistricting after every census, making it a regular high-stakes event.[4]
  2. The 1990s-2000s: Geographic information systems (GIS) and voter databases gave mapmakers detailed information about every household: party registration, voting history, campaign donations, age, income, race, and education.[4]
  3. 2010: One party used those tools at national scale.

REDMAP: How Gerrymandering Was Industrialized

The plan

In 2009, Chris Jankowski, who ran the Republican State Leadership Committee’s redistricting operation, recognized an opportunity. The 2010 elections fell in a census year, meaning whoever controlled state legislatures after November 2010 would draw the congressional and legislative maps used for the entire next decade.[2][3]

The project was called REDMAP: the Redistricting Majority Project. It targeted 107 state legislative races in 16 states, focusing on swing states where control of the legislature was within reach: Wisconsin, Michigan, Ohio, Pennsylvania, North Carolina, and Florida.[2]

Karl Rove publicly championed the concept. He wrote in the Wall Street Journal: “He who controls redistricting can control Congress.”[3]

The cost: approximately $30 million, invested in cheap state legislative races rather than expensive Senate or gubernatorial campaigns.[2][3]

The results

The 2010 elections were a Republican wave. But REDMAP ensured the wave’s effects would last a decade:

  • Republicans gained approximately 700 state legislative seats.[2]
  • Twenty legislative chambers flipped from Democratic to Republican control.[2]
  • Republicans took full control of 11 state legislatures.[2]
  • Republicans won control of redistricting in 10 of the 15 states that would be redrawing congressional maps.[2]

After the election, Jankowski declared: “Regardless of what happens in Washington, the Democrats will not soon recover from what happened to them on a state level on Tuesday.”[3]

How they used the power

Using sophisticated redistricting software, Republican mapmakers drew districts that packed Democratic voters into a handful of seats where they’d win by enormous margins (wasting those excess votes) and cracked remaining Democratic voters across many districts where they’d be narrowly outnumbered.[4]

Thomas Hofeller, described as “the master of the modern gerrymander,” was the key operative. After his death in 2018, his daughter discovered thousands of files on four hard drives and 18 thumb drives documenting his work across Arizona, Florida, Maryland, Mississippi, Missouri, Ohio, Tennessee, Virginia, and other states. A professor found Hofeller had manually entered African American voting-age population data into nearly every draft of his North Carolina mapping software.[9]

The defining data point: 2012

In the 2012 House elections, Democratic candidates received nearly 1.4 million more votes than Republican candidates (48.4% to 47.1%). Republicans kept the House majority, 234 to 201.[1][2]

This was one of only five times in American history that the party winning the popular vote failed to win the House majority.[1]

David Daley, author of “Ratf**ked,” wrote: “The Republicans spent $30 million on this and they were able to build themselves a firewall, a full Chamber of Congress for a decade.”[3]

They took credit publicly

The RSLC published a review on their own website connecting their 2010 state wins to the 2012 House majority. Republican strategist Ben Ginsberg, in an endorsement of David Daley’s book documenting the strategy, characterized it as “shadowy, but thus far, legal hacking, splicing, and dicing of congressional districts to secure Republican domination.”[2][3]


What It Looked Like in Practice

North Carolina

When courts struck down the original maps as racial gerrymanders, the legislature was ordered to draw new ones. State Rep. David Lewis, chairman of the redistricting committee, stated openly: “I propose that we draw the maps to give a partisan advantage to 10 Republicans and three Democrats, because I do not believe it’s possible to draw a map with 11 Republicans and two Democrats.”[10]

Wisconsin

Republicans drew maps in secret at a law firm’s offices. Legislators were required to sign confidentiality agreements. The result: in 2018, Democrats won all statewide offices and the popular vote but captured only 36 of 99 Assembly seats. Princeton’s Gerrymandering Project calculated the maps had a 1-in-60,000 probability of occurring by chance.[6]

The maps stood for 12 years until the Wisconsin Supreme Court struck them down in December 2023 on state constitutional grounds.[6]

Pennsylvania

The resulting 7th congressional district was so contorted that at its narrowest point it was barely wider than a restaurant parking lot, snaking through suburban Philadelphia to connect noncontiguous Republican areas.[7]

In 2018, the Pennsylvania Supreme Court struck down the maps as an illegal partisan gerrymander violating the state constitution’s “free and equal” elections clause. It was the first time a state court threw out congressional boundaries in a partisan gerrymandering case.[7]

Ohio

This may be the most instructive case for understanding why gerrymandering is so hard to fix.

In 2015, Ohio voters overwhelmingly approved a constitutional amendment creating a redistricting commission and banning partisan gerrymandering. It passed with over 70% of the vote, with support from both parties.[8]

In 2018, voters approved a second reform amendment, also with over 70%.[8]

The Republican-controlled redistricting commission drew aggressively gerrymandered maps anyway. The Ohio Supreme Court struck them down. The commission submitted new maps. The court struck those down too. This happened seven times.[8] The commission simply refused to comply with the court orders.

In 2024, reformers launched a new ballot initiative. Republican officials wrote ballot summary language stating the measure “required” the commission “to gerrymander.” Voters rejected it, apparently confused by the misleading description.[8]


Democrats Do It Too

This is not a one-party problem. Democrats gerrymander when they have the power.

Maryland: After the 2010 census, Democrats redrew a safely Republican district to be heavily Democratic. A federal court found the map “violates the First Amendment.” After the 2020 census, they drew another aggressive map. A state judge ruled it a “product of extreme partisan gerrymandering.” Both maps were eventually redrawn.[11]

Illinois: After the 2020 census, Democrats drew one of the most aggressively gerrymandered maps in the country. The Princeton Gerrymandering Project gave it failing grades in partisan fairness, competitiveness, and geographic features. The map reduced Republican representation from 5 to 3 of 17 seats.[13]

New York: In 2022, Democrats drew a heavily pro-Democratic map. New York’s highest court blocked it in a 4-3 decision, ruling it violated the state’s 2014 redistricting reform. A court-appointed special master drew replacement maps.[14]

The scale question

Both parties do it. The scale is not equal. In the most recent redistricting cycle, Republicans controlled the drawing of 177 congressional districts compared to 49 for Democrats. The Brennan Center found 11 Republican-drawn maps with extreme partisan bias compared to 4 drawn by Democrats.[4]

The reason is structural: Republicans hold more state government “trifectas” (governor plus both legislative chambers), giving them more opportunities to gerrymander. REDMAP was unique not because Republicans invented gerrymandering but because they industrialized it at national scale with $30 million in coordinated funding, sophisticated technology, and a strategy specifically designed to control redistricting for a decade.[2][3]


The Supreme Court Said It Couldn’t Help

Rucho v. Common Cause (2019)

This is the case that closed the courthouse door.

The Court combined two cases: Republican gerrymandering in North Carolina and Democratic gerrymandering in Maryland. In a 5-4 ruling, Chief Justice Roberts wrote that partisan gerrymandering may be “incompatible with democratic principles” but that “partisan gerrymandering claims present political questions beyond the reach of the federal courts.”[5]

Roberts told litigants to seek remedies through state courts or Congress instead.

Justice Kagan’s dissent: “Of all times to abandon the Court’s duty to declare the law, this was not the one. The practices challenged in these cases imperil our system of government… Partisan gerrymanders debased and dishonored our democracy… Someplace along this road, ‘we the people’ become sovereign no longer.”[5]

The catch-22

Roberts said “go to state courts or Congress.” But:

  • States that tried ballot-measure reform (Ohio) faced officials who ignored the results.[8]
  • State court remedies depend on the partisan makeup of state supreme courts. When North Carolina’s court flipped from Democratic to Republican in 2022, it reversed its own anti-gerrymandering ruling.[5]
  • Congressional remedies (the For the People Act, the Freedom to Vote Act) have been filibustered in the Senate.[15]

And with yesterday’s Louisiana v. Callais ruling, the Court has now made it nearly impossible to challenge maps on racial grounds as well, since states can claim partisan motivation (which courts can’t review) for maps with racial effects.[16]


What Voters Have Done About It

When given the chance, voters of both parties have consistently supported reform:

StateYearWhat voters approvedMargin
Ohio2015Redistricting commission, gerrymandering ban70%+
Ohio2018Congressional redistricting reform70%+
Michigan2018Independent citizen redistricting commission61% (carried 67 of 83 counties)
Colorado2018Independent redistricting commissionApproved
Utah2018Independent redistricting commissionApproved
Virginia2020Bipartisan redistricting commission65.7%

California’s independent commission, created in 2008, has been widely studied. Before the commission, only 5.2% of districts had competitive elections. Afterward: 14.6%. The Public Policy Institute of California found the commission “largely satisfied expectations that it would produce plans that are fair to each major party.”[4]

Michigan’s “Voters Not Politicians” initiative collected over 425,000 signatures and carried 67 of 83 counties, including both red and blue areas. The commission includes 4 Democrats, 4 Republicans, and 5 independents, selected randomly.[4]


What Gerrymandering Does to Elections

The practical effects go beyond which party wins:

Fewer competitive races: Only about 69 of 435 House seats were rated competitive in 2024. Twenty states had zero competitive districts.[4]

Primaries decide everything: A 2022 Unite America report found that just 8% of eligible voters cast ballots in partisan primaries for “safe” seats, yet those primaries effectively determined the winners in 83% of House races. When the general election is predetermined, the real election is the primary, where turnout is low and voters are more ideologically extreme.[4]

More extreme candidates: Stanford research found that extreme candidates are winning primaries and general elections more often than at any point in at least 30 years. Safe districts incentivize candidates to appeal to their party’s base rather than the broader electorate.[4]

Representation doesn’t match the vote: In 2012, Democrats won 1.4 million more House votes but lost the House. In 2018 Wisconsin, Democrats won statewide but captured 36 of 99 Assembly seats.[1][6]


The Counter-Arguments

”Gerrymandering is just part of politics. Both sides do it.”

Both sides do it. The question is whether that makes it acceptable. Voters in both red and blue states have repeatedly voted to ban it, often by margins above 60%. The practice is broadly unpopular regardless of which party benefits.[4]

“REDMAP was just good strategy. Democrats could have done the same.”

They could have and didn’t. Democrats had no comparable national redistricting strategy in 2010. Whether that reflects a strategic failure or a difference in priorities is debatable. What is documented is that REDMAP’s architects publicly took credit for converting $30 million in state legislative spending into a decade of House control, and that the resulting maps produced outcomes where the party that won fewer votes kept the majority.[2][3]

“Independent commissions are undemocratic. Elected officials should draw maps.”

Elected officials drawing maps have a direct conflict of interest: they are choosing their own voters. Independent commissions in California, Michigan, and other states have produced more competitive elections and maps rated fairer by nonpartisan analysts. Voters who approved these commissions did so through democratic means (ballot initiatives), often by large margins.[4]

“Population sorting explains the Republican advantage, not gerrymandering”

Population sorting is real: Democrats cluster in urban areas, naturally “wasting” votes in landslide city districts. This gives Republicans a structural advantage even with fair maps. But research consistently finds that sorting accounts for only part of the advantage. FiveThirtyEight’s analysis estimated gerrymandering accounts for less than 25% of polarization, with sorting being larger. But for seat allocation specifically, the Brennan Center estimated gerrymandering gave Republicans an advantage of approximately 16 House seats in 2024, well beyond what sorting alone explains.[4]


Where Things Stand Now

After the 2020 redistricting cycle, maps were generally fairer than after 2010, due to more independent commissions, more divided state governments, and more state court challenges. But significant gerrymandering persists in states controlled by one party.

Yesterday’s Louisiana v. Callais ruling adds a new dimension: the Court has now made it nearly impossible to challenge racially discriminatory maps in federal court, on top of making partisan gerrymandering challenges impossible after Rucho.[16] States that want to draw maps that disadvantage minority voters can now claim partisan rather than racial motivation, and courts cannot review either claim.

Six states enacted new congressional maps between the 2024 and 2026 elections. Before 2025, only two states had conducted voluntary mid-decade redistricting since 1970. The redistricting arms race is accelerating.

Congress could ban partisan gerrymandering through legislation. The Freedom to Vote Act would have created a statutory ban enforceable in federal court. It was filibustered.[15]

Voters have shown, repeatedly and across party lines, that they want fair maps. The question is whether the institutions that draw those maps will listen.


Sources

1. AP/PBS NewsHour: Analysis Shows Gerrymandering Benefited GOP in 2016 (June 2017)

2. Wikipedia: REDMAP (Redistricting Majority Project)

3. WBUR/Bill Moyers: How Republicans Weaponized Gerrymandering Through REDMAP

4. Brennan Center for Justice: Gerrymandering Explained

5. Wikipedia: Rucho v. Common Cause (2019)

6. CBS News: Wisconsin Supreme Court Strikes Down GOP-Drawn Legislative Maps (December 2023)

7. Brennan Center: Pennsylvania Supreme Court Confirms Congressional Map Is Illegal (2018)

8. Ohio Capital Journal: Ohio Gerrymandering, A Brief and Awful History (October 2024)

9. NPR: Deceased GOP Strategist’s Daughter Makes His Redistricting Files Public (January 2020)

10. Roll Call: When Does Partisan Gerrymandering Cross the Line? (March 2019)

11. NBC News: Maryland Judge Rules Congressional Map Unconstitutional (2022)

12. Library of Congress: Gerrymandering, The Origin Story

13. Washington Post: Illinois Democrats’ Gerrymandered Map (September 2021)

14. NPR: New York’s Congressional Redistricting Map Rejected by Court (April 2022)

15. Campaign Legal Center: What the Freedom to Vote Act Means for Partisan Gerrymandering

16. Slate: The Supreme Court’s Conservatives Just Issued the Worst Ruling in a Century (April 2026)