California Proposition 50 proposes temporarily transferring authority to draw the state's congressional district maps to the California Legislature through 2030, after which authority would return to the independent California Citizens Redistricting Commission.
December 31, 2030
high
temporal
Policy description of the proposed change to who controls congressional redistricting in California and the duration of that temporary transfer.
California Proposition 50 is a ballot measure that would temporarily return authority to draw congressional districts from the state's nonpartisan redistricting commission to the California Legislature, with approved maps scheduled to take effect starting in 2026.
January 01, 2026
high
temporal
Describes the policy change that Proposition 50 would enact regarding who controls congressional map-drawing and when new maps would take effect.
California Proposition 50, as described in the measure, would establish temporary congressional maps to be used for the 2026, 2028, and 2030 U.S. House elections and would have those maps replaced after the 2030 U.S. Census when the California Citizens Redistricting Commission draws new congressional maps.
January 01, 2026
high
temporal
Provisional duration and replacement mechanism for maps under California Proposition 50
Courts can reject congressional district maps if a map unduly favors one political party and can adopt remedial maps proposed by plaintiffs in redistricting lawsuits.
November 13, 2025
high
temporal
Describes judicial powers and remedies available in redistricting litigation.
Redrawing congressional district boundaries (redistricting) can change the partisan composition and electoral competitiveness of a district.
November 13, 2025
high
temporal
Describes the durable effect of boundary changes on partisan balance and competitiveness.
Mid-decade redistricting is the practice in which state governments redraw electoral district maps between decennial censuses, typically to alter partisan composition ahead of upcoming elections.
November 05, 2025
high
definition
General definition and purpose of mid-decade (mid-cycle) redistricting
Partisan redistricting (gerrymandering) can be used to shift the partisan lean of specific congressional districts, potentially converting districts held by one party into districts more favorable to the other party.
November 05, 2025
high
process
General mechanism and effect of partisan-driven redistricting on electoral competitiveness
In the United States, state legislatures in some states have the authority to enact congressional redistricting maps, enabling legislative majorities to implement maps that favor a particular party.
November 04, 2025
high
procedural
Where legislatures control redistricting, the majority party can draw maps that produce partisan advantages.
Ballot measures can be used to alter or replace existing redistricting mechanisms or congressional district maps.
November 04, 2025
high
procedural
Voters can use ballot initiatives or referenda to change who draws district lines or to approve new maps.
Ohio's state constitution required the Ohio Redistricting Commission to adopt new congressional districts because the prior districts had been adopted after the 2020 census without bipartisan support.
October 31, 2025
high
legal
Describes a constitutional trigger for redistricting in Ohio tied to how prior maps were adopted after the 2020 census.
As of 2025, Tennessee's 9th Congressional District is the state's only congressional district that leans Democratic under the congressional lines drawn by Tennessee Republicans.
October 08, 2025
high
political
Partisan lean of Tennessee's congressional districts under the current (2025) map.
State legislatures controlled by a political party can redraw congressional district maps (redistricting) in ways that influence the partisan composition of U.S. House seats.
September 11, 2025
high
temporal
Redistricting by state legislatures is a durable political process used to alter district boundaries and can affect which party is favored in House districts.
Redistricting methods, including legislative-controlled map drawing versus independent commissions, can change the partisan composition of electoral districts by altering which voters are included and thereby potentially flip which party holds a seat.
January 01, 2025
high
process
General principle about how different redistricting authorities and map changes affect partisan outcomes.
Republican lawmakers in Tennessee carried out redistricting in 2022 that divided Nashville and produced multiple congressional districts drawn to favor Republican candidates.
January 01, 2022
high
political_process
Summary of the 2022 redistricting process and its effect on Nashville's congressional district boundaries.
A congressional map enacted in Indiana in 2021 gave the Republican Party a 7-2 advantage in the state's U.S. House delegation.
January 01, 2021
high
temporal
Outcome of the 2021 redistricting for Indiana's congressional districts.
In Rucho v. Common Cause (U.S. Supreme Court, 2019), the Supreme Court ruled that federal courts cannot adjudicate claims of partisan gerrymandering.
June 27, 2019
high
legal
Judicial precedent limiting federal-court review of partisan-map challenges.
California voters gave congressional redistricting authority to an independent citizens commission in 2010.
January 01, 2010
high
institutional
California's voters created an independent commission to draw congressional district lines as a durable allocation of redistricting authority.
Racial gerrymandering, which involves drawing electoral district lines to intentionally target or dilute the voting power of racial minority groups, violates the federal Voting Rights Act.
August 06, 1965
high
legal
Legal principle governing redistricting and minority voting rights under U.S. federal law.
State legislatures can conduct redistricting outside the decennial census cycle (mid-decade redistricting), allowing them to redraw congressional district maps between census years.
high
structural
Describes the process known as mid-decade or off-cycle redistricting.
Federal law (28 U.S.C. §2284) provides for convening a three-judge district court to hear certain cases that challenge the apportionment of congressional districts or seek statewide relief.
high
legal
Procedural mechanism used in federal litigation over congressional district maps and statewide injunctive relief.