Redistricting and Gerrymandering
How politicians choose their voters
Every ten years following the census, congressional and state legislative districts are redrawn to reflect population changes. This redistricting process has enormous political consequences, determining which party controls legislatures and how competitive elections will be. Gerrymandering—drawing districts to advantage one party—has reached sophisticated levels using computer modeling, raising fundamental questions about representative democracy.
Why Redistricting Happens
The Constitution requires House seats to be reapportioned among states every ten years based on the census, ensuring equal representation as populations shift. States gaining population gain House seats; states losing population lose seats. Within each state, district boundaries must be redrawn to ensure roughly equal population per district (the "one person, one vote" principle from Reynolds v. Sims). State legislatures also redraw their own districts. This regular redrawing creates opportunities for partisan manipulation through gerrymandering.
Who Controls Redistricting
In most states, the state legislature draws congressional and state legislative maps, subject to the governor's veto. This means the party controlling state government following the census controls redistricting for the next decade. Some states use independent commissions to reduce partisan manipulation, including Arizona, California, Colorado, and Michigan. A few states have only one congressional district, avoiding redistricting. The control of state legislatures in census years (2020, 2030, etc.) thus has outsized importance.
What Is Gerrymandering
Gerrymandering is drawing district boundaries to advantage one party or group. The term comes from Massachusetts Governor Elbridge Gerry, who approved a salamander-shaped district in 1812. Modern gerrymandering uses sophisticated data on voter behavior, demographics, and past results to draw maps with precision impossible in earlier eras. The party drawing maps can dilute opposition by "cracking" (spreading opponents across many districts) or "packing" (concentrating opponents in few districts to waste votes).
Partisan Gerrymandering Tactics
Effective gerrymandering creates many districts with comfortable but not overwhelming majorities for the map-drawing party, while packing opposition voters into few districts they win overwhelmingly. For example, Republicans might create districts they win 55-45 while Democrats win their districts 80-20, wasting Democratic votes. Or Democrats might crack Republican voters across multiple districts where they're minorities. The result: a party can win a majority of seats while receiving a minority of total votes statewide. Computer modeling has made this engineering highly effective.
Racial Gerrymandering and the VRA
The Voting Rights Act prohibits redistricting that dilutes minority voting power. This led to creation of "majority-minority districts" where racial minorities constitute a majority, ensuring minority representation. However, packing minority voters into few districts can also help Republicans by concentrating Democratic-leaning voters, creating controversy over whether such districts empower or marginalize minorities. The Supreme Court has limited the VRA's requirements while striking down some racial gerrymanders, creating complex legal standards.
Legal Limits on Gerrymandering
Districts must have roughly equal population. They must comply with the Voting Rights Act regarding racial considerations. They must be geographically contiguous. Beyond these, federal courts have largely declined to police partisan gerrymandering. In Rucho v. Common Cause (2019), the Supreme Court ruled that partisan gerrymandering claims are non-justiciable political questions beyond federal court authority. Some state courts under state constitutions have struck down partisan gerrymanders. This leaves partisan gerrymandering largely unchecked except by voters and state-specific reforms.
Impact on Democracy and Polarization
Gerrymandering makes most districts safe for one party, eliminating general election competition. The only meaningful election is the primary, incentivizing candidates to appeal to base voters rather than moderates. This contributes to polarization as representatives fear primary challenges from their party's extreme. It also creates representatives who don't reflect statewide sentiment. Voters in gerrymandered states have less influence over outcomes, potentially depressing turnout. The relationship between gerrymandering and polarization is debated, but safe seats clearly reduce electoral accountability.
Reform Efforts
Independent redistricting commissions in states like California, Colorado, and Michigan aim to reduce partisan manipulation by having non-politicians draw maps. Criteria like compactness, preserving communities of interest, and competitiveness can constrain gerrymandering. Some propose multi-member districts or proportional representation as more fundamental reforms. However, abolishing gerrymandering requires those in power to give up advantages, making reform politically difficult. Ballot initiatives and constitutional amendments have achieved success in some states, offering a path around resistant legislatures.
Key Takeaways
- ✓Congressional and legislative districts are redrawn every ten years following the census to reflect population changes
- ✓In most states, the legislature controls redistricting, giving the majority party power to draw favorable maps
- ✓Gerrymandering allows parties to engineer durable majorities even without winning majority support statewide
- ✓The Supreme Court ruled partisan gerrymandering is a political question beyond federal court jurisdiction
- ✓Gerrymandering contributes to polarization by making primaries more important than general elections in safe districts
- ✓Independent commissions and state constitutional requirements offer potential reforms to reduce partisan manipulation