What Is Gerrymandering? The Law, the Mid-Decade Maps and the 2026 House

By Dr. AtlasPublished Sep 17, 2026

Gerrymandering is the drawing of election district lines to give one political party or group an advantage. The word dates to 1812, when Massachusetts Governor Elbridge Gerry approved districts “drawn to aid the Democratic-Republican Party” and a Federalist newspaper said one of them “resembled a salamander,” the Supreme Court has recounted. ^[1]

What is gerrymandering? Cracking and packing

Mapmakers have two basic techniques. In the Supreme Court's words, a “cracked” district is one in which a party's supporters “are divided among multiple districts, so that they fall short of a majority in each,” and a “packed” district is one in which they “are highly concentrated, so they win that district by a large margin.” ^[1]

Who draws congressional districts, and what the law requires

The Constitution says House members are “chosen every second Year by the People of the several States,” that seats are “apportioned among the several States” by population, and that the count is taken “within every subsequent Term of ten Years.” ^[4]

After each census, a formula set by Congress, “the method of equal proportions,” divides the 435 House seats among the states, with “no State to receive less than one Member.” ^[12][13] Since the 2020 census, each member has represented an average of 761,169 people. ^[13]

Drawing the lines inside a state is a separate step, redistricting, done “in the manner provided by the law” of that state. ^[12] The Elections Clause says the “Times, Places and Manner” of congressional elections “shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations.” ^[4]

A 1967 federal law adds a rule for every state with more than one seat: it must have “a number of districts equal to the number of Representatives,” with “no district to elect more than one Representative.” ^[5]

Is gerrymandering legal? What the Supreme Court has said

It depends on the claim. In Rucho v. Common Cause, decided June 27, 2019, the Court held 5–4 that “partisan gerrymandering claims present political questions beyond the reach of the federal courts.” ^[1] The majority pointed instead to state courts, because “state statutes and state constitutions can provide standards and guidance,” and to Congress's power under the Elections Clause. ^[1] Federal courts keep a role in “two areas—one-person, one-vote and racial gerrymandering,” the majority said. ^[1]

On race, the newest rule is Louisiana v. Callais, decided 6–3 on April 29, 2026. The Court held that a Louisiana map drawn with an additional majority-Black district was “an unconstitutional gerrymander,” because “the Voting Rights Act did not require Louisiana to create an additional majority-minority district.” ^[2]

Justice Samuel Alito's majority opinion said Section 2 of the Voting Rights Act “imposes liability only when the evidence supports a strong inference that the State intentionally drew its districts to afford minority voters less opportunity because of their race,” and called partisan advantage “a constitutionally permissible criterion.” Justice Elena Kagan, dissenting, wrote that under the ruling “a State can, without legal consequence, systematically dilute minority citizens' voting power.” ^[2]

Mid-decade redistricting: is it allowed?

“Congressional districts typically are redrawn at the start of each decade,” the Associated Press noted on September 4, 2026, but a redistricting battle “that Trump urged GOP-run states to launch last year” has “spread to more than a dozen states.” ^[3] The Supreme Court summarized the sequence in December 2025: “Texas adopted the first new map, then California responded with its own map for the stated purpose of counteracting what Texas had done.” ^[14]

Federal law does not forbid redrawing between censuses. In League of United Latin American Citizens v. Perry (2006), about the map Texas enacted in October 2003, Justice Anthony Kennedy wrote: “With respect to a mid-decade redistricting to change districts drawn earlier in conformance with a decennial census, the Constitution and Congress state no explicit prohibition.” ^[6] The statewide challenge was rejected, though the Court held that one redrawn district violated the Voting Rights Act. ^[6]

Texas redistricting: the 2025 map and the Supreme Court

Texas has 38 congressional districts. The 89th Legislature enacted a new plan, PlanC2333, in its second called session, and as of September 17, 2026 the Texas Legislative Council lists it among the “district plans in effect for the 2026 elections.” ^[7]

Challengers contended “that the legislature's motive was predominantly racial,” and on November 18, 2025 a divided three-judge federal court “enjoined the use of the new map in the 2026 elections.” ^[14] On December 4, the Supreme Court stayed that order, saying the lower court “failed to honor the presumption of legislative good faith” and “improperly inserted itself into an active primary campaign.” ^[14]

Justice Alito, concurring, wrote that “the impetus for the adoption of the Texas map (like the map subsequently adopted in California) was partisan advantage pure and simple.” Justice Kagan, dissenting with Justices Sotomayor and Jackson, objected that the Court “reverses that judgment based on its perusal, over a holiday weekend, of a cold paper record.” ^[14] On April 27, 2026, the Court summarily reversed the district court's judgment, the same three justices dissenting. ^[15]

California and North Carolina: a ballot measure and a bill

California's Proposition 50, placed on the ballot by the Legislature, passed on November 4, 2025 by 7,453,339 votes to 4,116,998, or 64.4% to 35.6%. ^[8][9] It requires “temporary use of new congressional district maps through 2030” and directs the state's independent commission “to resume enacting congressional district maps in 2031.” ^[8]

North Carolina's Senate Bill 249, “Realign Congressional Districts 2025,” passed its final Senate reading 26–20 and its House second reading 66–48, and became Session Law 2025-95 on October 22, 2025. ^[16]

Missouri's 5th District: why the 2022 map is in use

Missouri lawmakers met in special session in 2025 “to dramatically reconfigure the 5th Congressional District, held by Democrat Emanuel Cleaver,” the AP reported. ^[3] The resulting act, House Bill No. 1, “repeals Missouri's existing congressional plan, and replaces it with new congressional boundaries that keep more counties intact,” the official ballot title says. ^[11]

In December, opponents “submitted over 300,000 petition signatures seeking to put the map to a vote of the people”; the secretary of state rejected the petition in August. On September 3, 2026, the Missouri Supreme Court ruled unanimously that the petition “was legal, sufficient, and timely” and that the post-2020 map “remains in full force and effect for the November 2026 general election,” the AP reported. ^[3]

A federal judge then issued a restraining order “directing Hoskins not to use any map except the one drawn in 2025,” Missouri Independent reported. ^[17] On September 10, the U.S. Supreme Court stayed that September 8 order pending appeal, and Secretary of State Denny Hoskins said his office “is directing local election authorities to use the 2022 congressional map.” ^[10][18]

As of September 17, 2026, that leaves the Kansas City-based 5th District voting on its 2022 lines, although state Sen. Rick Brattin, the Republican nominee, “won an August primary in the reshaped 5th Congressional District.” ^[3][17] The state has asked the 8th U.S. Circuit Court of Appeals to order the 2025 map used; arguments were set for September 17, Missouri Independent reported on September 16. ^[17] The 2025 map is also on the November 3 ballot as Proposition A: a “no” vote “will leave in place the congressional district boundaries enacted in 2022.” ^[11]

After Callais: Florida, Tennessee, Louisiana and Alabama

Florida's Legislature “passed new congressional districts just hours after the ruling,” Tennessee “adopted new U.S. House districts a week after the ruling,” and Louisiana lawmakers on May 29 passed a map “eliminating one of the state's two majority-Black House districts,” the AP reported. ^[19] “The Supreme Court in June granted Alabama permission to switch maps,” the AP reported later. ^[20]

• Ledger races in these states: Texas 9th District race 2026: Mealer vs. Gutierrez, Texas 38th District race 2026: Bonck vs. McDonough, Tennessee 9th District race 2026: Taylor vs. Pearson, Louisiana 6th District race 2026: Miguez vs. Banks, Florida 13th District race 2026: Luna vs. Gray, California 5th District race 2026: McClintock vs. Masuda.
• Every new map: the 2026 House elections guide.

What supporters and opponents say

The case for leaving maps to elected officials is in the Rucho majority opinion: barring lawmakers from weighing partisan interests “would essentially countermand the Framers' decision to entrust districting to political entities.” ^[1] The case against is in Justice Kagan's dissent, which said the gerrymanders before the Court “debased and dishonored our democracy.” ^[1]

California's official voter guide printed both sides of the 2025 fight. Supporters said Proposition 50 “approves temporary, emergency congressional district maps to counter Donald Trump's scheme to rig next year's congressional election.” Opponents said it “was written by politicians, for politicians” and “eliminates voter protections that ban maps designed to favor political parties.” ^[8]

What the maps mean for the House

All 435 seats are filled every two years; 218 is a majority. ^[4][13] The Clerk's tally dated September 16, 2026 showed 218 Republicans, 214 Democrats, 1 independent and 2 vacancies. ^[21] See what midterm elections are.

What congressional district am I in?

The House's Find Your Representative tool works by “matching your ZIP code to your congressional district,” but reports districts “for the current Congress.” ^[22] It adds a caution: boundary updates “may have changed what district you vote(d) in during 2026 primary and general elections, but will not change the Congressional district in which you are currently represented” until January 2027. ^[22] To see the district on your November ballot, check the sample ballot or voter record from your state or county election office; the Ledger's Texas and Missouri guides link to the official tools.

Questions and answers