America's Gerrymanders: How State Legislatures Rig the Map Every Decade

Every ten years, after the census, state legislatures redraw the boundaries of congressional districts. In theory, this is a technical exercise in ensuring equal representation. In practice, it is the most consequential form of election-rigging still permitted under American law. The party that controls a state legislature gets to draw lines that determine which party will win most congressional seats for the next decade—and courts have largely declared themselves unable, or unwilling, to stop it.

The stakes are not theoretical. After the 2020 census, Republicans controlled redistricting in states with 187 congressional seats; Democrats controlled states with 75. The resulting maps handed Republicans a structural advantage of 16 to 20 seats before a single vote was cast, according to analyses by the Princeton Gerrymandering Project and the Brennan Center for Justice. In North Carolina, a state where presidential elections are decided by two percentage points, Republicans drew a map that gave them 10 of 14 House seats in 2022—a 71% seat share from a roughly 50-50 electorate. In Wisconsin, Republicans won 64% of state assembly seats in 2022 despite receiving 48% of the statewide vote.

This is gerrymandering: the deliberate manipulation of district boundaries to predetermine election outcomes. The word comes from Massachusetts Governor Elbridge Gerry, who in 1812 approved a salamander-shaped district designed to favour his party. Two centuries later, the practice has been refined into a computational science. Modern mapmakers use voter files, precinct-level election data, and optimization algorithms to draw districts with surgical precision—packing opposition voters into a few districts they win overwhelmingly, or cracking them across many districts where they consistently lose.

A Constitutional Void

The United States Constitution says almost nothing about how district lines should be drawn. Article I, Section 4 gives states the power to determine the "times, places and manner" of congressional elections, subject to alteration by Congress. For most of American history, districts were drawn haphazardly—some states used multi-member districts, others at-large elections. It was not until the Supreme Court's 1964 ruling in Wesberry v. Sanders that districts were required to be roughly equal in population—"one person, one vote."

But equal population does not mean fair representation. The Constitution does not prohibit partisan gerrymandering—drawing lines to advantage one party over another—and for decades, courts grappled with whether they should. In 1986, in Davis v. Bandemer, the Supreme Court held that partisan gerrymandering could, in theory, be unconstitutional if it met a high bar of harm. But no court ever found a map that met that standard.

Then, in June 2019, the Supreme Court closed the door entirely. In Rucho v. Common Cause, a 5-4 decision written by Chief Justice John Roberts, the Court held that partisan gerrymandering claims present "political questions beyond the reach of the federal courts." Roberts acknowledged that extreme gerrymandering is "incompatible with democratic principles"—but argued that there was no manageable judicial standard to determine when partisanship had gone too far. The majority opinion cited the lack of a "limited and precise" test and concluded that federal courts should stay out.

Justice Elena Kagan, in dissent, called the ruling a "tragedy for the system of government the framers gave us." She pointed to multiple proposed standards—the efficiency gap, partisan symmetry, the mean-median difference—that courts could use. But the majority declined. In effect, Rucho declared that while partisan gerrymandering might be wrong, it is not a problem the federal Constitution forbids.

The Numbers

The post-2020 redistricting cycle produced some of the most aggressive gerrymanders in modern history. In Texas, Republicans added two congressional seats and redrew the map to lock in a 25-13 advantage—despite the state voting 52-47 for Trump in 2020. In Georgia, Republicans redrew the 6th and 7th districts, both narrowly won by Democrats in 2020, to make them safely Republican. In Florida, Governor Ron DeSantis vetoed the legislature's map and imposed his own, dismantling two Black-majority districts and flipping four Democratic seats.

Democrats have gerrymandered, too. In Illinois, the party redrew the map to create a projected 14-3 Democratic advantage in a state Biden won 57-41. In New York, Democrats attempted an aggressive gerrymander that would have netted them 22 of 26 seats—but the state's highest court struck it down under New York's constitution, which, unlike the federal one, prohibits partisan gerrymandering. A court-appointed special master drew a more balanced map.

But the overall effect is asymmetric. Republicans control more state legislatures, particularly in large states, and have been more willing to push maps to the constitutional limit. An analysis by the nonpartisan Cook Political Report found that, after 2020 redistricting, Republicans held a 16-seat advantage from gerrymandering alone. By comparison, after the 2010 census, the advantage was estimated at 11 seats. The trend is toward more aggressive line-drawing, not less.

A State-by-State Patchwork

With federal courts out of the picture, the only remedy is state-level. Some states have banned partisan gerrymandering in their own constitutions—most notably, California, Colorado, Michigan, Virginia, and New York. Others have established independent redistricting commissions. California's Citizens Redistricting Commission, created by ballot initiative in 2008, uses a 14-member body selected by lottery from applicant pools, with no legislators allowed. The commission is required to prioritize geographic compactness, respect for communities of interest, and competitiveness—in that order.

The results are measurable. In Michigan, voters approved Proposal 2 in 2018, creating an independent commission. The 2022 map produced a 7-6 Democratic seat advantage in a state Biden won 51-48—a much closer match to the electorate than the previous Republican-drawn map, which had yielded a 9-5 Republican advantage despite statewide votes favouring Democrats. Similarly, Virginia's bipartisan commission, approved in 2020, produced competitive maps—though disputes over criteria sent the process to the state supreme court.

But independent commissions are rare, and their adoption is difficult. In Ohio, voters approved a constitutional amendment in 2015 requiring bipartisan support for redistricting, and a second amendment in 2018 creating a commission. Republicans ignored both. The 2021 map passed on party-line votes with no Democratic support, violating the state constitution. The Ohio Supreme Court struck it down—four times. Republicans simply re-passed near-identical maps and ran out the clock. By the time litigation concluded, the 2022 election had been held under an unconstitutional map. The court had no mechanism to enforce its rulings.

The Democracy Gap

Gerrymandering produces a structural distortion in representation that compounds over time. Safe seats reduce electoral competition: in 2022, only 36 of 435 House races were decided by margins under five percentage points. The median victory margin was 23 points. When seats are not competitive, incumbents do not need to appeal to swing voters—they need only to avoid a primary challenge. The result is polarization. Members from gerrymandered districts face no incentive to compromise; their only electoral risk is being outflanked from within their own party.

The problem is bipartisan in structure but asymmetric in effect. Democratic voters are more geographically concentrated in urban centres, which makes them easier to pack into a few districts. Republican voters are more dispersed across suburbs and rural areas, which makes cracking easier to execute. This gives Republicans a natural geographic advantage—even before any intentional gerrymandering. Deliberate line-drawing amplifies it.

The distortion also affects policy. In Wisconsin, Republicans have held supermajorities in the state legislature since 2011 despite losing the statewide popular vote in seven of the last nine elections. That supermajority has allowed them to block Medicaid expansion, override vetoes, and pass voting restrictions—all while representing a minority of voters. In North Carolina, a Republican supermajority repeatedly overrode the Democratic governor's vetoes, enacting abortion bans and election law changes that a majority of voters opposed in polling.

2030 Looms

The next census is four years away. After 2030, the process will repeat: every state will redraw its districts based on new population counts, and whichever party controls the legislature will control the map. In battleground states—Pennsylvania, Wisconsin, Arizona, Georgia—the outcome of the 2028 state legislative elections will determine congressional representation for the following decade. For reformers, this presents both urgency and opportunity. Ballot initiatives in Missouri and Arkansas are attempting to establish independent commissions before 2030. But in many states, legislators must approve such measures—and legislators have little interest in relinquishing the power to choose their own voters.

Congress could act. The House passed H.R. 1, the For the People Act, in 2019 and 2021, which would have required states to use independent commissions for congressional redistricting. The bill died in the Senate both times, lacking the 60 votes needed to overcome a filibuster. A narrower bill, the Freedom to Vote Act, met the same fate in 2022. With Republicans controlling the House in 2023–2024, no such legislation has been introduced.

What Is to Be Done

The most effective remedy is the one already being tested: state constitutional amendments establishing independent commissions, adopted by ballot initiative where possible. California, Michigan, Colorado, and Arizona demonstrate that such commissions can produce fairer maps. The process is not perfect—Colorado's commission deadlocked in 2021 and required court intervention—but imperfect neutrality is better than intentional distortion.

For states without ballot initiatives, the path is harder. State courts can intervene if state constitutions provide a hook—as New York's and Pennsylvania's do. Litigation under the Voting Rights Act remains possible in cases where gerrymandering dilutes minority voting power, though the Supreme Court has narrowed those protections significantly. The most durable solution is federal legislation requiring independent redistricting—but that requires Congress to act, and Congress has not.

In the meantime, transparency helps. Publishing draft maps, releasing underlying data, and allowing public comment cannot prevent gerrymandering—but it can make the manipulation visible. Algorithmic tools now allow citizens to draw and compare alternative maps, demonstrating when a legislature's map is an outlier. In Wisconsin, the League of Women Voters used such tools to submit alternative maps to the court, which adopted one in 2024 after years of litigation.

Lines and Power

Gerrymandering is not a glitch in American democracy; it is a feature that has been carefully preserved. The Constitution permits it, the Supreme Court has refused to constrain it, and state legislatures have every incentive to entrench it. The result is a system in which many elections are decided not by voters, but by the officials who draw the lines. That this happens in plain sight, with maps published and analysed, does not make it less effective. It makes it, in a sense, worse—a form of rigging that proceeds openly because no one has the power, or the will, to stop it. The 2030 census will offer another chance. Whether reformers can seize it depends on whether voters understand that the real election is not in November, but in the backrooms where the maps are drawn.