What have courts said about citizen‑only apportionment and the constitutionality of excluding non‑citizens?

1. The constitutional baseline: Article I, the Fourteenth Amendment and longstanding practice

The Constitution’s Apportionment Clause and the Fourteenth Amendment direct that Representatives be apportioned “according to their respective numbers” and that states count the “whole number of persons,” a textual scheme the federal government has read and courts have applied as requiring total‑person counts—an approach reinforced by a long, unbroken governmental practice that the Court has used to justify administrative choices about census questions and apportionment methods ^{[1] [2] [5]}.

2. One person, one vote and judicial review of apportionment schemes

Beginning with Baker v. Carr and crystallized in Reynolds v. Sims, the Supreme Court moved apportionment disputes from “political thickets” into the courtroom by ruling that malapportionment dilutes citizens’ votes and that the Equal Protection Clause supplies judicially manageable standards for review, a doctrinal backdrop that treats representation as tied to population and to the protection of individual voting weight rather than to categories of citizenship ^{[6] [7] [8]}.

3. Attempts to replace total‑person with citizen‑only counts and how courts reacted

During the Trump administration, efforts to exclude undocumented immigrants from the apportionment base—most notably an executive memorandum—prompted litigation; a three‑judge district court struck the policy down, finding it inconsistent with the constitutional responsibility to count whole persons and with the statutory and historical record, and lower courts blocked the exclusion pending further review, with advocates and scholars arguing that citizen‑only apportionment would violate settled law ^{[3] [4]}.

4. Scholarly and institutional consensus against citizen‑only apportionment

Law reviews, advocacy groups, and the Campaign Legal Center—relying on the constitutional text, Section 2’s history, and the nation’s census practice—conclude that counting only citizens would be “inconsistent with U.S. jurisprudence” and would upend congressional and state representation; courts have generally deferred to the weight of precedent and practice that the apportionment base is the whole resident population ^{[3] [4] [2]}.

5. Arguments that complicate the picture: Section 2, political choices, and Congressional latitude

There is an alternative thread in the sources: Section 2 of the Fourteenth Amendment historically references citizens in the context of penalizing disenfranchisement (language about “male citizens”), and some commentators and justices have at times urged caution about judicial re‑writing of constitutional structures, which leaves room for political branches to argue different constructions of the apportionment formula; yet the dominant judicial posture—and administrative practice—has favored total‑person counting, with the Supreme Court recognizing Congressional primacy in some apportionment mechanics while still enforcing one‑person/one‑vote principles ^{[9] [10] [11]}.

6. Bottom line and remaining legal uncertainty

Courts to date have consistently rejected or blocked efforts to convert apportionment into a citizen‑only exercise, relying on constitutional text, precedent and centuries of practice to count every person in a state for reapportionment; while alternative readings invoking Section 2 or deference to political branches exist and have been urged by some actors, the weight of federal court decisions and scholarly analysis treats citizen‑only apportionment as constitutionally and jurisprudentially hostile to established law—though a definitive, modern Supreme Court ruling on a full merits challenge to citizen‑only apportionment would ultimately be dispositive ^{[1] [7] [3] [4]}.