What redistricting is & why it matters
Redistricting is redrawing electoral district boundaries so each district has roughly equal population. The principle is “one person, one vote” — every district should represent the same number of people.
The distinction matters: apportionment decides how many seats a state gets. Redistricting decides where those seats go. Apportionment is a math problem. Redistricting is a power struggle.
When done fairly, redistricting produces fair maps that reflect population changes. When done strategically, it predetermines election outcomes for a decade. The strategic version is gerrymandering.
- 31
- states where legislatures draw maps
- 4
- states with independent commissions
- 13
- states that reallocate prisoner data
- 15+
- states redrawing maps mid-decade
How redistricting works step by step
The normal cycle follows three stages.
The Redistricting Process
| Stage | What happens | Who does it |
|---|---|---|
| 1. Census | The Census Bureau counts every person in the United States. | Federal government (constitutionally required every 10 years) |
| 2. Apportionment | The 435 House seats are divided among states based on population. | Census Bureau calculates; Congress accepts |
| 3. Redistricting | Each state draws new district lines for its allotted seats. | Varies by state: legislature, commission, or court |
Legal requirements for every map
All congressional maps must follow three rules:
- Equal population. Districts must be as nearly equal in population as practicable. For congressional maps, the standard is strict: even small deviations can be challenged.
- Voting Rights Act compliance. Maps cannot dilute the voting power of racial or language minorities. (The Callais ruling narrowed this standard in April 2026.)
- Contiguity. Each district must be one connected piece of territory. You cannot draw a district with disconnected parts.
States can add their own requirements: compactness, preserving counties or cities, keeping communities of interest together, or prohibiting maps drawn to favor a party. Whether those rules are enforced depends on who draws the maps and who reviews them.
Who draws the maps in each state
Brennan Center reports that legislatures control congressional redistricting in 31 states. That means the party in power draws the lines that determine whether it stays in power.
How States Draw Congressional Maps
| Method | How it works | States |
|---|---|---|
| Legislature | Lawmakers pass the map like regular legislation. Governor can veto in most states. | 31 states |
| Independent commission | Commissioners draw and approve final maps. Current lawmakers cannot serve. | AZ, CA, CO, MI (+ AK, ID, MT, WA for some maps) |
| Advisory commission | Recommends maps but legislature has final say. | IA, ME, NY, VA, and others |
| Court-drawn | Used when litigation blocks or invalidates a legislature or commission plan. | Varies by cycle (OH, PA, NC have recent court-drawn maps) |
Iowa’s model is unique. A nonpartisan agency draws maps without access to political data. The legislature votes yes or no but cannot modify the maps. Iowa consistently produces some of the most competitive elections in the country.
Congressional maps vs. state legislative maps
The same state can use one process for congressional districts and a different process for state House and Senate districts. Congressional maps require near-exact population equality. State legislative maps require “substantial” equality, a slightly looser standard. Both must comply with the Voting Rights Act.
How the 2020 Census changed the map
The Census Bureau released apportionment results on April 26, 2021. The pattern: Sun Belt states gained representation. Rust Belt and Northeast states lost it.
| Category | Value |
|---|---|
| Texas | 2 |
| Florida | 1 |
| North Carolina | 1 |
| Colorado | 1 |
| Montana | 1 |
| Oregon | 1 |
| California | -1 |
| Illinois | -1 |
| Michigan | -1 |
| New York | -1 |
| Ohio | -1 |
| Pennsylvania | -1 |
| West Virginia | -1 |
Source: Census Bureau, 2020 apportionment. Texas gained 2 seats. Seven states lost 1 each.
Texas gained the most seats and immediately used them to draw maps favoring the party in power. Seven states that lost seats faced harder choices about which communities to split. The new maps became the targets of litigation that is still ongoing.
The 2025-2026 Mid-Decade Redistricting Wave
Federal law does not prohibit redrawing maps between census cycles. Some states ban it. Many do not address it. Nine states have already redrawn congressional maps outside the normal cycle. Twelve more are considering it or in litigation. This is the most active mid-decade redistricting since the 1800s.
Sources: Ballotpedia, Brennan Center, LLS Redistricting
| State | Status | Trigger | Seat impact |
|---|---|---|---|
| Texas | Redrawn (R advantage) | Governor special session | +5 R (court blocked use for 2026) |
| Florida | Redrawn (R advantage) | Legislature special session (post-Callais) | +4 R (challenged in court) |
| North Carolina | Redrawn (R advantage) | Legislature | +1 R |
| Ohio | Redrawn (R advantage) | Redistricting commission | +2 R |
| Missouri | Redrawn (R advantage) | Legislature | +1 R |
| Tennessee | Redrawn (R advantage) | Legislature special session (post-Callais) | +1 R |
| Louisiana | Redrawn (R advantage) | Court/legislature post-litigation | Majority-Black district erased |
| California | Redrawn (D advantage or court-ordered) | Counter-map after GOP push | +5 D |
| Utah | Redrawn (D advantage or court-ordered) | Court-ordered | +1 D |
| Alabama | Pending or in litigation | Federal court blocked 2023 map. Court-drawn plan restored. | TBD |
| Georgia | Pending or in litigation | Governor called special session | TBD |
| Indiana | Pending or in litigation | Legislature considering | TBD |
| Kansas | Pending or in litigation | Legislature considering | TBD |
| Maryland | Pending or in litigation | House passed mid-decade map. Senate has not acted. | TBD |
| New Jersey | Pending or in litigation | Commission considering | TBD |
| New York | Pending or in litigation | Considered but not in time for 2026 | TBD |
| South Carolina | Pending or in litigation | House passed plan. Senate rejected it. | TBD |
| Virginia | Pending or in litigation | Democrats considered redistricting. Courts said no. | TBD |
| Nebraska | Pending or in litigation | Under consideration | TBD |
| Illinois | Pending or in litigation | Under consideration | TBD |
| Colorado | Pending or in litigation | Under consideration | TBD |
Completed mid-decade redraws
| State | Trigger | Party | Seat impact |
|---|---|---|---|
| Texas | Governor special session | R | +5 R (court blocked for 2026) |
| California | Counter-map after GOP push | D | +5 D |
| Florida | Legislature special session (post-Callais) | R | +4 R (challenged in court) |
| Louisiana | Court/legislature post-litigation | R | Majority-Black district erased |
| North Carolina | Legislature | R | +1 R |
| Ohio | Redistricting commission | R | +2 R |
| Missouri | Legislature | R | +1 R |
| Tennessee | Legislature special session (post-Callais) | R | +1 R |
| Utah | Court-ordered | D | +1 D |
Republicans gained seats in 7 states. Democrats gained in 2. Courts blocked or constrained maps in Texas and Florida. The Callais ruling accelerated the wave by making racial gerrymandering claims harder to win.
How the Callais ruling changed everything
On April 29, 2026, the Supreme Court ruled 6-3 in Louisiana v. Callais that Louisiana’s second Black-majority congressional district was an unconstitutional racial gerrymander.
Before and After Callais
| Before Callais | After Callais | |
|---|---|---|
| VRA Section 2 claims | Gingles framework (40 years of precedent): prove racial bloc voting + geographic compactness | Must prove intentional discrimination (much harder standard) |
| Majority-minority districts | Required where conditions met | Can be challenged as racial gerrymanders |
| State flexibility | States had to justify majority-minority districts as VRA compliance | States have more room to redraw without federal constraints |
| Political effect | Protected minority representation in several states | Opened door for dismantling minority districts nationwide |
Within days of the ruling, Florida passed new maps. Tennessee eliminated its sole majority-Black district by splitting Memphis into three Republican districts. Georgia’s governor called a special session for June 17. Alabama’s court-ordered second majority-Black district was vacated and remanded.
The gerrymandering explainer covers packing, cracking, the court cases, and what independent commissions look like when they work.
Where prisoners count changes who has power
The Census counts incarcerated people where the prison is located, not where they lived before incarceration. This inflates the political power of rural districts with large prisons and reduces representation in the urban and suburban communities prisoners came from.
Thirteen states now reallocate prisoner data to home addresses for redistricting: Maryland, New York, California, Colorado, Connecticut, Delaware, Montana, Nevada, New Jersey, Pennsylvania, Rhode Island, Virginia, and Washington. Illinois will join them starting with the 2030 cycle.
Roughly half the U.S. population now lives in a jurisdiction that has ended prison gerrymandering at some level. Maryland is widely cited as a low-cost reform model. The Prison Policy Initiative tracks reform efforts nationwide.
What you can do
- Know who draws your maps. If your state legislature controls redistricting, the party in power decides the lines. Check the Brennan Center’s tracker.
- Support independent redistricting commissions. Ballot initiatives created commissions in Arizona, California, Colorado, and Michigan. Common Cause and Campaign Legal Center provide model legislation and campaign support.
- Vote in state supreme court elections. After Rucho v. Common Cause (2019), federal courts cannot hear partisan gerrymandering claims. State courts are the only venue left. These races are low-turnout and high-impact.
- Support prison gerrymandering reform. If your state still counts prisoners at the prison location, push your state legislature to reallocate. The Prison Policy Initiative has state-specific resources.
- Track mid-decade redraws. Democracy Docket and Ballotpedia maintain live trackers of redistricting litigation and map changes.
The Freedom to Vote Act and the John Lewis Voting Rights Advancement Act would establish federal standards for fair maps and restore preclearance. Neither has passed. Until they do, state-level reform and state courts are the primary tools available.
The gerrymandering explainer covers packing, cracking, and what independent commissions look like when they work. The primary elections explainer shows why safe districts shift power to primaries. Check your state page for local redistricting context.