Moore v. Harper — Independent State Legislature Theory
Moore v. Harper, 600 U.S. 1 (2023), is the Supreme Court's 6-3 decision rejecting the most aggressive version of the independent state legislature (ISL) theory — the claim that the Constitution's Elections Clause and Electors Clause vest in state legislatures an authority over federal elections so plenary that state courts cannot review legislative enactments under state constitutions. Chief Justice Roberts's majority opinion held that state courts retain authority to review state legislative actions governing federal elections under state constitutional provisions, and that state courts' interpretations of state law do not wholly escape federal judicial review. The case arose from North Carolina's Republican-controlled legislature drawing a congressional map that the North Carolina Supreme Court struck down as an extreme partisan gerrymander under the state constitution. The legislature argued that under the ISL theory, the state supreme court had no authority to override the legislature's redistricting choices because the Elections Clause assigns power exclusively to the "Legislature" of each state — not to state courts, governors, or state constitutional provisions. Moore v. Harper is a landmark preservation of state court authority over election law, but its acknowledgment that federal courts may review state court rulings on federal election statutes has left significant constitutional questions unresolved for future cases.
Current Law (2026)
| Parameter | Value |
|---|---|
| Case citation | Moore v. Harper, 600 U.S. 1 (2023) |
| Constitutional basis | U.S. Const. art. I, § 4 (Elections Clause); art. II, § 1 (Electors Clause) |
| Holding | State courts retain authority to review state legislative election laws under state constitutions; ISL theory rejected in its strongest form |
| ISL theory | Rejected: "Legislature" in Elections Clause does not mean state legislatures are free from state constitutional constraints or state judicial review |
| Federal review limit | State courts cannot "transgress the ordinary bounds of judicial review" or "arrogate to themselves the power vested in state legislatures" — federal review available when state court interpretations exceed reasonable bounds |
| Partisan gerrymandering | Rucho v. Common Cause (2019) — federal courts cannot review federal partisan gerrymandering claims; state courts may review under state constitutions |
| Redistricting effect | North Carolina map ultimately redrawn; underlying state constitutional standard later modified by new NC Supreme Court |
Legal Authority
- U.S. Const. art. I, § 4, cl. 1 — Elections Clause: "The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations"
- U.S. Const. art. II, § 1, cl. 2 — Electors Clause: "Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors" — the presidential election analogue to the Elections Clause
- 52 U.S.C. § 20501 — Help America Vote Act — federal framework for election administration that interacts with state legislative authority over elections
- 52 U.S.C. § 10301 — VRA § 2 — federal constraint on state legislative redistricting decisions regardless of the ISL theory
- Moore v. Harper, 600 U.S. 1 (2023) — ISL theory rejected; state courts retain authority over state election laws under state constitutions; federal review available when state courts exceed reasonable interpretive bounds
- Rucho v. Common Cause, 588 U.S. 684 (2019) — Federal courts lack jurisdiction over federal partisan gerrymandering claims; state courts remain an avenue under state constitutional law
- Bush v. Gore, 531 U.S. 98 (2000) — Florida Supreme Court's interpretation of election law reviewed under federal constitutional standards; implicit precursor to ISL theory debates
- Smiley v. Holm, 285 U.S. 355 (1932) — "Legislature" in Elections Clause means the legislative process of the state, including gubernatorial veto; foundational precedent against pure ISL theory
Key Mechanics
Moore v. Harper (2023) rejected the "independent state legislature" (ISL) theory — the claim that the Elections Clause grants state legislatures plenary, unreviewable authority over federal election rules, free from state constitutional limitations and state court review. North Carolina Republicans relied on the ISL theory to argue that the state supreme court had no power to strike down a congressional redistricting map as violating the state constitution's free elections provisions. The Supreme Court ruled 6-3 against the ISL theory: Chief Justice Roberts's majority held that "the Elections Clause does not insulate state legislatures from the ordinary exercise of state judicial review" — state courts may review state election laws under state constitutions, and federal courts may review whether a state court's interpretation has "transgressed the ordinary bounds of judicial review" such that it effectively makes new law rather than applying existing state constitutional standards. The decision's practical effect was to preserve the status quo: state supreme courts retained their usual role in reviewing election laws for state constitutional compliance, and the ISL theory — which could have dramatically limited the role of state constitutions and courts in election administration — was rejected. Moore did leave open a narrow federal oversight role: federal courts may intervene if a state court exceeds reasonable bounds in interpreting state election law, though what "exceeds reasonable bounds" means in practice remained to be worked out in subsequent cases. By the time the decision was issued, North Carolina had redrawn its maps through normal legislative processes.
How It Works
The North Carolina Gerrymandering Case
After the 2020 census, North Carolina's Republican-controlled General Assembly drew a congressional district map that would have delivered Republicans a significant majority of the state's 14 congressional seats. The North Carolina Supreme Court — then with a Democratic majority — struck down the map as an extreme partisan gerrymander under the state constitution's equal protection and free elections provisions. The court ordered a replacement map drawn with less partisan advantage.
The North Carolina legislative leadership petitioned the Supreme Court, arguing that the North Carolina Supreme Court had no authority to review the legislature's congressional redistricting under the state constitution. The theory: the Elections Clause vests power over "the Times, Places and Manner of holding Elections for Senators and Representatives" in "the Legislature" of each state — meaning the state legislature alone, unconstrained by state constitutional limitations or state court review. Under this reading, only federal law (through congressional action or federal courts) could constrain state legislative power over federal elections; state constitutions and state courts would be irrelevant to federal election law.
This is the "independent state legislature" theory — the legislature operates independently of the state constitutional structure when it acts on federal elections.
The Majority's Rejection of ISL Theory
Roberts's majority opinion, joined by Justices Kavanaugh, Barrett, Sotomayor, Kagan, and Jackson, rejected the ISL theory in its strongest form. The majority relied on two main grounds:
Historical practice: From the founding through the present, state legislatures have operated within state constitutional frameworks when regulating federal elections. Governors have vetoed election legislation; state courts have reviewed election laws under state constitutional provisions; state constitutional requirements have constrained legislative redistricting. The ISL theory had no support in historical practice and would require the Court to conclude that every state for 230 years had been misunderstanding the Elections Clause.
Text and structure: The Elections Clause refers to "the Legislature" as a state institution — and state legislatures are creatures of state constitutions. They derive their existence, powers, and procedures from state constitutions. Smiley v. Holm (1932) had already held that "Legislature" in the Elections Clause includes the governor's veto power — meaning the Elections Clause's reference to state legislatures contemplates the full state legislative process, including constitutional constraints. State courts enforcing state constitutional requirements are not usurping legislative power; they are enforcing the state constitutional framework within which the legislature operates.
The Caveat: Federal Review of State Court Decisions
While rejecting the strongest ISL theory, the majority acknowledged that federal courts retain authority to review state court interpretations of state election laws to ensure that state courts do not "transgress the ordinary bounds of judicial review" or "arrogate to themselves the power vested in state legislatures." The Court stopped short of defining precisely when a state court's interpretation would cross the constitutional line — but it made clear that federal review is available when a state court's reading of state law is so far outside the reasonable interpretive range that it effectively substitutes judicial will for legislative choice.
This caveat — the acknowledgment that some state court decisions on election law are subject to federal review — is potentially significant. It leaves open the possibility that in a closely contested election, federal courts could review state court decisions on election law procedures and find that state courts exceeded their interpretive authority. The dissenting justices (Thomas, Gorsuch, and Alito) agreed that federal review was available but would have applied a more aggressive version of ISL theory; the majority's middle path invited future litigation about where the line falls.
The North Carolina Procedural Twist
After the Supreme Court granted certiorari in Moore, the North Carolina Supreme Court — its composition changed after the 2022 elections gave Republicans a majority — reversed its earlier decision striking down the gerrymander and reinstated the original legislative map. The Supreme Court considered whether this development mooted the case; it held that the case was not moot (because federal courts retained jurisdiction to review state court decisions under the federal standard) and proceeded to decide the constitutional question. The North Carolina saga illustrated the interplay between judicial elections, legislative redistricting, and constitutional law.
The 2020 Election and ISL Theory
The ISL theory gained urgent political salience during the 2020 post-election litigation. Advocates for overturning state election results argued that state courts had improperly extended mail voting and other procedures through state constitutional rulings — and that under ISL theory, these rulings were invalid because the Elections Clause reserved those decisions to state legislatures alone. The Supreme Court rejected emergency applications in that context, but the broader constitutional question remained live. Moore v. Harper answered the underlying constitutional question in the non-emergency redistricting context.
How It Affects You
If you are a voter or election law advocate: Moore v. Harper preserves state courts as a forum for challenging state election laws under state constitutional provisions — a significant protection given that federal courts cannot review federal partisan gerrymandering claims (Rucho) and that VRA preclearance is gone (Shelby County). State constitutional litigation challenging gerrymandering, voter ID laws, polling place decisions, and other election restrictions remains a viable avenue in states with strong state constitutional voting rights provisions. The majority's caveat about federal review of state court decisions creates some uncertainty — but it does not eliminate state courts as effective checks on state legislative power over elections. Understanding your state constitution's voting rights provisions is increasingly important as federal constitutional and statutory protection has been narrowed.
If you are a redistricting advocate or litigator: Moore v. Harper is a green light for state constitutional challenges to partisan gerrymandering and other redistricting abuses in states where state courts are willing to enforce state constitutional standards. After Rucho (2019) closed the federal courthouse doors to federal partisan gerrymandering claims, state courts became the primary forum for such challenges. Moore preserves that forum. The key variable is state constitutional law: states like Pennsylvania, Michigan, Ohio, and North Carolina have state constitutional provisions that state courts have applied to redistricting; states with less robust state constitutional voting protections offer fewer opportunities. The majority's caveat about extreme state court interpretations being subject to federal review adds a layer of uncertainty, but does not fundamentally undermine state court authority.
If you are a state legislator or election official: Moore v. Harper means state legislatures are not free agents when regulating federal elections — they remain subject to state constitutional constraints and state judicial review, just as they are for state elections. Redistricting decisions must comply with state constitutional requirements (including state equal protection provisions, free elections clauses, and specific anti-gerrymandering provisions where they exist). Election law changes are subject to state court review. Governors may veto election legislation. The ISL theory's rejection means the state constitutional framework — including checks and balances — applies to federal election administration. Federal constraints (VRA, federal election law, constitutional guarantees) also apply independently. Legislative redistricting and election law decisions should be designed to withstand both state and federal constitutional scrutiny.
If you are a constitutional law scholar or political observer: Moore v. Harper is a significant but incomplete resolution of the ISL theory controversy. The majority's rejection of the strongest ISL version preserves the constitutional status quo — state legislatures are subject to state constitutional constraints and state courts when regulating federal elections. But the majority's acknowledgment that federal courts can review state court interpretations that exceed "ordinary bounds of judicial review" has significant implications: in a contested election, this standard could invite federal court intervention in what had been understood as state law questions. The dissent's three justices would have applied a more aggressive form of the theory; the majority's six may have rejected the most extreme version while keeping the door open to more targeted review in future cases. Post-Moore, the litigation battleground has shifted to defining the limits of the "ordinary bounds" standard.
State Variations
Moore v. Harper establishes a federal constitutional floor: state courts retain authority to review state legislative election laws under state constitutions, and state legislatures are subject to state constitutional constraints. State variation operates within this framework:
State constitutional voting rights provisions: State constitutions vary enormously in their provisions relevant to redistricting and elections. Pennsylvania's constitution has been interpreted to prohibit extreme partisan gerrymandering; North Carolina's has been interpreted similarly (before the NC Supreme Court reversed). Michigan adopted an independent redistricting commission by ballot initiative. States with stronger state constitutional voting rights provisions offer more robust state court protection against legislative overreach.
Independent redistricting commissions: Some states — California, Arizona, Colorado, Michigan — use independent redistricting commissions rather than legislative redistricting. Arizona State Legislature v. Arizona Independent Redistricting Commission (2015) upheld independent commissions as a valid exercise of state constitutional power delegated by voters; Moore does not disturb this. Commissions reduce the partisan gerrymandering risk that motivated the ISL theory litigation.
State court electoral composition: State supreme courts are often elected, making their composition subject to electoral cycles. The North Carolina experience — where the political composition of the state supreme court changed between the trial and Supreme Court decision — illustrates how state judicial elections can affect the protection state courts provide. States with appointed judiciaries may be more insulated from partisan pressure on election law rulings.
State anti-gerrymandering provisions: Some states have adopted explicit constitutional prohibitions on partisan gerrymandering (including Colorado, Michigan, and Ohio); others lack such provisions. In states with explicit prohibitions, state court challenges to partisan redistricting plans have a stronger textual foundation.
Pending Legislation
- Freedom to Vote Act / John Lewis Voting Rights Advancement Act: Federal legislation that would establish national standards for redistricting, voting access, and election administration — providing federal statutory constraints on state legislative election authority independent of the ISL theory debate. Not enacted as of 2026.
- Electoral Count Reform Act (2022): Enacted after the 2020 post-election litigation, this Act clarified the procedures for counting electoral votes and limited the grounds for congressional objections — addressing some of the ISL theory concerns that arose in the 2020 context without resolving the underlying constitutional question.
- State-level redistricting reform: Multiple states have considered or enacted independent redistricting commission systems since Rucho closed federal courts to partisan gerrymandering claims. Arizona, Colorado, Michigan, and California have commissions; several other states are considering similar measures.
Recent Developments
- 2023 — Moore v. Harper decided: The Supreme Court issued its ruling rejecting strong ISL theory in June 2023, just before the 2024 redistricting and election cycle. The ruling preserved state courts as forums for election law challenges while acknowledging federal review of extreme state court interpretations.
- 2023 — North Carolina follow-on: After Moore, the North Carolina Supreme Court (with its changed composition) reversed its prior ruling and reinstated the original Republican gerrymander. The legislature subsequently enacted new maps that were also challenged. The North Carolina redistricting saga illustrated the instability of state court protection when judicial compositions change.
- 2024 — Trump v. Anderson and presidential ballot access: The Supreme Court's unanimous ruling in Trump v. Anderson (2024) — holding that states cannot unilaterally disqualify federal candidates under the Fourteenth Amendment's disqualification clause without congressional action — addressed a related Elections Clause question about state authority over federal elections, reinforcing Moore's framework.
- 2024 — Electoral College administration: The post-2020 debate about presidential electors and ISL theory influenced the Electoral Count Reform Act (2022) and generated ongoing academic attention to the Electors Clause's application to presidential elections — the second clause in which ISL theory had been invoked.
- 2025 — State redistricting litigation: Post-Moore, redistricting litigation has continued in multiple states under state constitutional provisions, with litigants testing the boundaries of state court authority and the federal review standard the majority left undefined.
- April 29, 2026 — Louisiana v. Callais, 24-109: A 6-3 Supreme Court (Alito majority; Kagan dissent) substantially narrowed VRA Section 2's vote-dilution doctrine, holding that Section 2 did not require Louisiana to create a second majority-Black district. While Moore preserved state constitutional review of partisan gerrymandering, Callais simultaneously reduced the federal statutory floor that constrains how states may dilute minority voting power — meaning state-court challenges under state constitutions may become an even more important venue for vote-dilution claims that previously could be brought as VRA Section 2 cases. As of May 2026, Alabama is asking the Supreme Court to lift the Allen v. Milligan injunction in light of Callais before the May 19, 2026 primary.