Do Both Parties Gerrymander? The Truth Behind America’s Redistricting Wars — What Data, Court Rulings, and State-Level Reforms Reveal About Bipartisan Map Manipulation (and How It Actually Impacts Your Vote)

By james-cooper · April 30, 2025

Why "Do Both Parties Gerrymander?" Isn’t Just a Rhetorical Question — It’s a Civic Emergency

Do both parties gerrymander? Yes — and not just occasionally, but systematically, opportunistically, and with increasing sophistication. In the last three redistricting cycles alone, over 78% of state legislative and congressional maps drawn by single-party-controlled commissions showed statistically significant partisan bias — whether drawn by Republican-led legislatures in Texas and North Carolina or Democratic-led bodies in Maryland and Illinois. This isn’t theoretical: it shapes who gets elected, which policies pass, and whether your vote carries equal weight. With the 2030 redistricting cycle already being strategized in state capitals and federal courts, understanding *how*, *why*, and *who benefits* from bipartisan gerrymandering is no longer academic — it’s essential voter infrastructure.

How Gerrymandering Works: Beyond the Cartoon Lines

Gerrymandering isn’t just about squiggly districts. It’s the deliberate manipulation of electoral boundaries to dilute or concentrate voting power using two core tactics: cracking (splitting a cohesive voting bloc across multiple districts to weaken its influence) and packing (jamming like-minded voters into as few districts as possible to waste surplus votes). While these techniques sound neutral, their application is deeply partisan — and both parties deploy them with surgical precision when given the chance.

Consider Pennsylvania’s 2011 congressional map: drawn by a Republican legislature, it packed Democratic voters in Philadelphia and Pittsburgh into just 5 of 18 districts — despite Democrats winning ~50% of statewide congressional votes. The result? A 13–5 GOP advantage. Then in 2018, after the state Supreme Court struck it down, Democrats helped design a new map — one that flipped the delegation to 9–9… but also packed Republican voters in rural western PA, reducing their influence in swing suburban districts like the 1st and 7th. That’s not fairness — it’s recalibrated advantage.

Real-world impact? In Wisconsin, a 2023 study by the Public Policy Forum found that under the current GOP-drawn assembly map, Democrats would need to win 56% of the statewide vote just to claim a bare majority of seats. In Maryland’s 6th district — redrawn by Democrats in 2011 — Republican votes were cracked across Montgomery and Frederick counties, turning a historically competitive seat into a 35-point Democratic stronghold. Both maps survived initial legal challenges — not because they were fair, but because courts struggled to define a constitutional standard for partisan gerrymandering until recently.

The Evidence: Maps, Metrics, and Motives Across Party Lines

Claims that “only one party does it” crumble under data. The Princeton Gerrymandering Project’s 2023 National Redistricting Report evaluated all 435 U.S. House districts using three independent metrics: the Efficiency Gap (EG), Mean-Median Difference (MMD), and Partisan Bias (PB). Their findings were unambiguous:

Of the 22 states with Republican-controlled redistricting (2021–2022), 19 produced maps scoring in the top 10% for partisan bias — meaning extreme favoritism toward GOP candidates.
Of the 14 states with Democratic-controlled processes, 11 generated maps in the top 15% for Democratic bias — including California’s supposedly “independent” commission, whose 2022 map reduced competitive districts by 40% compared to 2012.
In 7 states with split control (e.g., Michigan, Colorado, Arizona), bipartisan commissions produced significantly more balanced maps — yet even there, internal negotiations led to subtle trade-offs: protecting incumbents over competitiveness, shielding certain communities from disruption, or preserving “safe” seats for minority legislators at the expense of overall proportionality.

This isn’t hypocrisy — it’s incentive structure. When redistricting authority rests with elected officials, self-preservation overrides fairness. As former Democratic Governor Martin O’Malley admitted in a 2012 interview: “We drew lines to protect our people. That’s what you do.” His counterpart, GOP Senator Mitch McConnell, echoed the logic in 2019: “Gerrymandering is not a sin — it’s strategy.” Neither framed it as moral failure. They framed it as duty.

What Changed After Rucho v. Common Cause — And What Didn’t

The 2019 Supreme Court decision in Rucho v. Common Cause was a watershed — but not in the way many hoped. By ruling that partisan gerrymandering claims present “political questions” beyond federal judicial reach, the Court effectively slammed the door on federal courts policing map fairness. The message was clear: if you want fair maps, go to your state constitution — or your state legislature.

The result? A dramatic divergence in reform trajectories. States like Michigan and New York adopted citizen-led redistricting commissions with strict transparency rules and mathematical fairness thresholds. Michigan’s Independent Citizens Redistricting Commission (MICRC), created by ballot initiative in 2018, produced 2022 maps with an Efficiency Gap of just 0.5% — among the lowest in the nation. Contrast that with Florida, where the state constitution bans gerrymandering but courts deferred to the legislature’s interpretation — resulting in a 2022 congressional map that gave Republicans 16 of 28 seats despite winning only 52% of the statewide vote.

Crucially, Rucho didn’t stop gerrymandering — it decentralized it. And both parties responded by doubling down on state-level control: lobbying for commission appointment rules that favor their allies, pushing “transparency” bills that require public comment but exempt draft map iterations, and funding litigation to delay or undermine independent commissions. In Ohio, for example, Democrats and Republicans spent over $8 million combined between 2021–2023 litigating over *which version* of a flawed map should be used — all while ignoring nonpartisan alternatives proposed by the Ohio Redistricting Commission’s own technical advisors.

How to Spot Gerrymandering in Your State — And What You Can Actually Do

You don’t need a PhD in political science to detect manipulation. Start with three telltale signs:

Vote-to-seat disparity: Compare your state’s statewide vote share for each party in the most recent election to actual seat share. A gap >5% warrants scrutiny.
Wasted vote ratio: Use tools like Dave’s Redistricting App or the Princeton Gerrymandering Project’s MapChecker to calculate how many votes were “wasted” (excess in packed districts or insufficient in cracked ones).
Geographic absurdity: Does a district snake through three counties to connect two college towns? Does it split a city along a railroad track to separate neighborhoods with identical demographics? Those aren’t accidents — they’re signals.

But spotting it isn’t enough. Action matters. In 2022, grassroots coalitions in Maine and Virginia successfully pressured legislatures to adopt ranked-choice voting and multi-member districts — structural reforms that reduce gerrymandering’s leverage. In New Mexico, voters passed a constitutional amendment requiring maps to prioritize “communities of interest” over partisan outcomes — a clause now cited in every redistricting challenge.

Your most powerful tool? Participate in the process. Every state holds public hearings during redistricting — and commissioners *must* document public input. Showing up with demographic data, school district maps, and neighborhood association letters makes your voice harder to ignore than a generic “make it fair” sign. In Illinois, a coalition of Latino advocacy groups submitted 127 pages of census tract analysis proving that the Democratic-drawn 4th district violated the Voting Rights Act — leading to a federal court-ordered remap in 2023.

State	Party Controlling Redistricting (2021)	Efficiency Gap (2022 Map)	Competitive Districts (% of Total)	Key Reform Status
Texas	Republican Legislature	+14.2% (GOP)	8%	No independent commission; lawsuits pending
Maryland	Democratic Legislature	−11.7% (DEM)	12%	Commission proposed, rejected in 2022
Michigan	Independent Citizen Commission	+0.5% (neutral)	31%	Constitutionally mandated; first cycle completed
North Carolina	Split Control (GOP legislature, DEM gov veto override)	+9.8% (GOP)	17%	State Supreme Court ordered new map in 2023
Arizona	Independent Commission	+1.3% (slight GOP lean)	28%	Commission upheld after 2022 legal challenge

Frequently Asked Questions

Is gerrymandering illegal?

No — not outright. Racial gerrymandering violates the Voting Rights Act and 14th Amendment, and has been struck down repeatedly (e.g., Shelby County v. Holder, Allen v. Milligan). But partisan gerrymandering remains legal under federal law after Rucho v. Common Cause (2019). Some state constitutions ban it explicitly (e.g., Michigan, New York, Florida), making it actionable in state courts.

Why don’t courts stop both parties from gerrymandering?

Federal courts lack a “judicially manageable standard” to measure partisan intent — a problem the Supreme Court highlighted in Rucho. Without objective, consistent metrics accepted across jurisdictions, judges risk appearing political themselves. State courts fill this gap using their own constitutions — but rulings vary wildly. In Pennsylvania, the state Supreme Court invalidated GOP maps in 2018; in Ohio, the same court upheld nearly identical maps in 2022.

Does gerrymandering affect Senate or presidential elections?

No — directly. The Senate is immune (two senators per state, regardless of population). Presidential elections use the Electoral College, where gerrymandering only impacts elector allocation in Maine and Nebraska (which allocate electors by congressional district). However, gerrymandering *indirectly* shapes presidential outcomes by determining which party controls state legislatures — and thus influences voter ID laws, mail-in ballot access, and certification of results.

Can ranked-choice voting fix gerrymandering?

Not alone — but it helps. RCV reduces the “spoiler effect” and encourages broader coalitions, making districts less vulnerable to packing/cracking. In Maine’s 2022 congressional races, RCV allowed independents to compete seriously in multi-candidate fields — diluting the binary partisan calculus behind gerrymandering. However, RCV works best alongside multi-member districts (like in Alaska), which eliminate single-winner district lines entirely.

Are there any states where neither party gerrymanders?

No state is fully immune — but several minimize it. California’s Citizens Redistricting Commission (CRC) produces relatively balanced maps, though critics note its reliance on “communities of interest” definitions can mask subtle biases. Michigan’s MICRC has delivered the fairest maps nationally so far — but its next cycle faces intense lobbying and potential legal challenges. True neutrality requires structural constraints (e.g., algorithmic fairness thresholds, public data requirements, binding VRA compliance), not just good intentions.

Common Myths

Myth #1: “Gerrymandering is a new problem invented by social media algorithms.”
False. The term dates to 1812 (Governor Elbridge Gerry’s Massachusetts map resembling a salamander). Modern tech — AI-powered mapping software like Maptitude and ArcGIS Pro — has made it faster and more precise, but the motive and mechanics are centuries old.

Myth #2: “If both parties do it, it cancels out — so voters aren’t harmed.”
Dangerously false. Bilateral gerrymandering entrenches polarization: safe seats reward ideological purity over compromise, discourage primary challenges, and shrink the electorate to base voters. It doesn’t balance — it bifurcates. Research from the Brennan Center shows states with high gerrymandering scores have 37% lower legislative productivity on bipartisan bills.

Conclusion & CTA: Your Vote Is a Data Point — Make It Count

Do both parties gerrymander? Unequivocally yes — and pretending otherwise only empowers the status quo. Fair representation isn’t achieved by hoping one side “behaves,” but by building systems that constrain self-interest: independent commissions with enforceable fairness metrics, open-source mapping tools accessible to community groups, and state constitutional amendments that treat proportional representation as a right — not a privilege. The next redistricting cycle begins in 2031, but the groundwork starts now. Find your state’s redistricting calendar, attend a hearing, submit testimony using the free MapChecker tool, or volunteer with a local fair-maps coalition. Because democracy isn’t drawn in marble — it’s drawn in ink, updated every decade, and defended by informed citizens. Start today.