What Is Gerrymandering?
Gerrymandering is the practice of drawing electoral district boundaries to give one political party, group, or incumbent an unfair advantage over their opponents. The term dates to 1812, when Massachusetts Governor Elbridge Gerry approved a redistricting plan that created an unusually shaped state senate district designed to favor his party. A newspaper cartoonist noted that the district resembled a salamander and combined Gerry's name with the animal to coin "Gerrymander."
Every ten years, after the census, all 435 congressional districts must be redrawn to reflect population changes. This process — called redistricting — is controlled in most states by the state legislature. Whichever party controls the legislature after the census controls the map, giving them enormous power over which party wins most House seats for the next decade.
Two Types of Gerrymandering
Partisan Gerrymandering
Drawing districts to maximize the number of seats won by one party, regardless of race or ethnicity. The party in power in the state legislature draws boundaries that dilute the opposing party's votes. In 2019, the Supreme Court ruled in Rucho v. Common Cause that federal courts cannot review partisan gerrymandering claims — it is a "political question" left to states and Congress. This effectively made partisan gerrymandering legal at the federal level.
Racial Gerrymandering
Drawing districts specifically to dilute the voting power of a racial or ethnic minority group. This is unconstitutional under the Equal Protection Clause of the 14th Amendment and remains subject to federal court review under the Voting Rights Act. Courts regularly strike down maps found to have intentionally diluted Black, Hispanic, or other minority voting power. The line between permissible "partisan" gerrymandering and unconstitutional "racial" gerrymandering is often the subject of litigation.
Packing and Cracking: The Two Techniques
Gerrymanderers typically use two complementary techniques to maximize their party's seat share:
Packing means concentrating as many opposition voters as possible into a single district. The opposition wins that district by a huge margin — say 80%–20% — but "wastes" tens of thousands of votes beyond what was needed to win. The surrounding districts become easier for the party drawing the map to win.
Cracking means splitting a concentrated group of opposition voters across multiple districts so they form a minority in each one and cannot elect any candidates. An urban area that might have elected two opposition-party representatives gets divided across four districts, each of which is won by the map-drawing party.
Used together, packing and cracking can allow a party that wins roughly 50% of the statewide vote to win 65–70% of the congressional seats. This is why gerrymandering is often described as politicians choosing their voters rather than voters choosing their politicians.
Who Draws the Maps?
In most states, the state legislature draws both congressional and state legislative maps. This means the party that wins the state legislature in November of a census year — 2010, 2020, 2030 — controls redistricting for the following decade.
However, a growing number of states have moved redistricting to independent or bipartisan commissions, specifically to reduce partisan manipulation. Key examples:
- California — Citizens Redistricting Commission (created by voters in 2008, expanded 2010)
- Arizona — Independent Redistricting Commission (created by voters in 2000)
- Michigan — Independent Citizens Redistricting Commission (created by voters in 2018)
- Colorado — Independent Legislative and Congressional Redistricting Commissions (created by voters in 2018)
- Virginia — Virginia Redistricting Commission (created by voters in 2020)
Maps drawn by independent commissions consistently produce more competitive districts and less extreme partisan distortion than legislatively-drawn maps.
The 2020 Redistricting Cycle
Republicans had a structural advantage in the 2020 redistricting cycle: they controlled more state legislatures than Democrats after the November 2020 elections. This allowed them to draw favorable maps in several large states:
Florida, Texas, North Carolina, Georgia — Republican-controlled legislatures drew aggressive maps that significantly boosted Republican seat projections. In Texas, the congressional delegation shifted from a 23R-13D split to a 25R-13D split under the new map.
Democrats controlled fewer states but attempted their own gerrymanders. New York drew an extremely aggressive Democratic map that was struck down by the state's Court of Appeals as a violation of a 2014 state constitutional amendment banning partisan gerrymandering. A court-drawn replacement map produced more competitive results in 2022. Maryland drew a heavily Democratic map that reduced Republican competitiveness in the 6th congressional district.
The net result of the 2020 cycle: Republicans gained a structural advantage of roughly 5-8 House seats compared to a neutral map.
Effect on the 2026 Midterms
Gerrymandering limits but does not eliminate competitive House districts. Some of the most genuinely competitive seats in the country exist precisely because they are in states with independent redistricting commissions — California, Arizona, Michigan and Colorado have produced a disproportionate share of true battleground seats.
Democrats need a net gain of 5 seats to retake the House majority in 2026. Most forecasters identify approximately 30-40 genuinely competitive districts. The structural map advantage Republicans built in 2020 makes the climb slightly steeper for Democrats, but macroeconomic conditions and presidential approval ratings historically matter far more than map geometry in wave elections.
Court challenges continue to reshape some maps. North Carolina's Supreme Court reversed course after a partisan shift in 2023, allowing a more Republican-friendly map. These legal battles make the competitive landscape for 2026 still somewhat fluid.
Supreme Court Rulings
Rucho v. Common Cause (2019)
The Supreme Court ruled 5-4 that federal courts cannot review partisan gerrymandering claims. Chief Justice Roberts wrote that partisan gerrymandering presents a "political question" beyond the reach of federal courts. The ruling does not prevent state courts from striking down maps under state constitutions, and several have done so.
Racial Gerrymandering Is Still Reviewable
Unlike partisan gerrymandering, racial gerrymandering remains subject to federal court review under the 14th Amendment's Equal Protection Clause and the Voting Rights Act. In Allen v. Milligan (2023), the Court upheld the Voting Rights Act and required Alabama to draw a second majority-Black congressional district. This ruling strengthened protections against racially discriminatory maps.
Frequently Asked Questions
Is gerrymandering legal?
It depends on the type. Partisan gerrymandering — drawing districts to favor one political party — is legal at the federal level after Rucho v. Common Cause (2019). Racial gerrymandering — drawing districts to dilute minority voting power — remains unconstitutional and is still subject to federal court review under the Equal Protection Clause and the Voting Rights Act.
Which states have independent redistricting commissions?
States with independent or bipartisan redistricting commissions include California, Arizona, Michigan, Colorado, Virginia, Hawaii, Idaho, Montana, New Jersey and Washington. These commissions were typically created by voter-approved ballot initiatives to reduce partisan manipulation of district maps.
How does gerrymandering affect the 2026 midterms?
Gerrymandering limits competitive districts but doesn't eliminate them. Republicans have a structural map advantage from the 2020 redistricting cycle, making Democrats' task of flipping 5 seats slightly harder. However, the most competitive seats in 2026 are concentrated in commission states (CA, AZ, MI, CO) where maps were drawn without partisan intent. Presidential approval ratings and economic conditions will likely matter more than the map itself.
