Franchise Amendments: Congress and the Right to Vote

The original Constitution said remarkably little about who may vote, leaving qualifications largely to the states. Four amendments changed that by removing specific grounds from the states’ reach, and each carries an enforcement clause allowing Congress to legislate against discrimination in state as well as federal elections. Together they form the textual floor of voting rights.

Learning them is a matter of matching a ground of exclusion to the right amendment, and the exercise is more precise than it first appears — because one of the four is narrower than people assume, and a great deal of voting doctrine sits outside all four and is handled by equal protection instead. This guide sets out each amendment, the enforcement power that gives them teeth, and the boundary with the fundamental-rights analysis.

Diagram of the four franchise amendments showing the 15th on race, the 19th on sex, the 24th on poll taxes in federal elections and the 26th on age eighteen, alongside the voting questions handled by equal protection instead — Fig. 75 · Match the ground of exclusion to the amendment — everything else is an equal protection problem.

The four amendments

Each amendment removes one ground from the permissible reasons for denying or abridging the vote, and each is worth stating in its own terms rather than paraphrased loosely.

Fifteenth Amendment. The right to vote may not be denied or abridged on account of race, colour, or previous condition of servitude. Section 2 gives Congress power to enforce it by appropriate legislation, and it is the constitutional foundation of federal voting-rights legislation.
Nineteenth Amendment. The right to vote may not be denied or abridged on account of sex — the constitutional basis of women’s suffrage.
Twenty-fourth Amendment. The right to vote may not be denied or abridged for failure to pay a poll tax or any other tax — in federal elections. That textual limitation is the source of the area’s best-known trap.
Twenty-sixth Amendment. The right to vote may not be denied or abridged on account of age for citizens who are eighteen years of age or older.

A compact way to hold them: fifteenth is race, nineteenth is sex, twenty-fourth is poll tax in federal elections, twenty-sixth is age eighteen and above. Note the shared verb across all four — denied or abridged. The amendments prohibit exclusion on the listed grounds; they are not general charters for regulating the machinery of elections, and a rule that burdens voting without discriminating on a listed ground must be attacked elsewhere.

The poll tax trap

The Twenty-fourth Amendment reaches federal elections only — elections for President, Vice President, senators and representatives. It says nothing about state and local elections, and a candidate who cites it against a state poll tax has cited the wrong provision.

State poll taxes are nonetheless unconstitutional, and the authority is Harper v. Virginia Board of Elections (1966), decided under the Equal Protection Clause. The reasoning is that the right to vote is fundamental and wealth is not a permissible basis for allocating it, so conditioning the franchise on payment is subject to strict scrutiny and cannot be justified. The result is the same, the route is different, and the distinction is examined constantly.

So the discipline on any poll-tax fact pattern is to read which election is involved before choosing the authority. Federal election, cite the Twenty-fourth Amendment. State or local election, cite Harper and equal protection. A complete answer mentions both and explains why the amendment does not reach the state case by its own terms.

Exam tip: check the type of election before naming the provision. The Twenty-fourth Amendment is textually limited to federal elections; a state poll tax falls under Harper and equal protection.

The enforcement power and the Voting Rights Act

The amendments would be of limited practical value without machinery, and the enforcement clauses supply it. Congress may enact appropriate legislation to enforce them, and it has — most importantly the Voting Rights Act of 1965, which provides sanctions and remedies for voter discrimination and reaches state as well as federal elections.

There is a constitutional limit on that power, and it is worth knowing because it is where enforcement legislation is actually litigated. Congress’s authority is remedial: it may enact measures that are congruent and proportional to the constitutional violations it seeks to remedy, but it may not redefine the substance of the right itself. Legislation supported by a record of documented discrimination and tailored to it stands on solid ground; a sweeping prophylactic regime with no such record is vulnerable.

The Reconstruction amendments are also the reason federal voting legislation can reach purely state elections. Ordinarily Congress would need to establish an enumerated power, and its authority over the conduct of state elections is limited. The enforcement clauses supply a direct and independent grant for the specific purpose of preventing discrimination in the franchise.

What the amendments do not cover

The great majority of modern voting litigation concerns grounds the amendments do not list, and that material belongs to the fundamental-rights branch of equal protection rather than to any amendment’s text.

Districting and vote dilution are the largest category. The one person, one vote principle requires substantial population equality between districts, and it derives from equal protection rather than from the franchise amendments. Ballot-access requirements, candidate filing fees, registration deadlines, residency rules and durational requirements are all assessed by weighing the burden imposed against the state’s justification. Wealth-based conditions fall under Harper. In each case the franchise amendments function as the textual floor — worth citing to establish that voting is constitutionally protected — with the analysis then proceeding under equal protection.

One boundary is jurisdictional rather than substantive. Claims that district lines were drawn to entrench a political party — partisan gerrymandering — were held non-justiciable in federal court in Rucho v. Common Cause (2019), on the ground that no manageable standard exists for deciding how much partisanship is too much. Racial gerrymandering claims remain fully justiciable, which makes the characterisation of the claim decisive.

Facts	Provision
Literacy test administered by race	Fifteenth Amendment
Women excluded from the ballot	Nineteenth Amendment
Poll tax in a congressional election	Twenty-fourth Amendment
Poll tax in a state election	Equal protection (Harper)
Eighteen-year-old refused the vote	Twenty-sixth Amendment
Unequal district populations	Equal protection
Federal legislation on state elections	Enforcement clauses
Partisan gerrymandering claim	Political question (Rucho)
Racial gerrymandering claim	Equal protection

Table 1 · Matching the facts to the correct provision.

Worked example

State N enacts a statute requiring every voter to pay a two-dollar registration fee before voting in any state or local election. Federal elections are unaffected. A resident who cannot afford the fee challenges the statute, relying on the Twenty-fourth Amendment.

The claimant is right about the outcome and wrong about the provision, and a good answer says both. The Twenty-fourth Amendment prohibits conditioning the vote on payment of a tax, but only in federal elections, and this statute is expressly confined to state and local contests. So the amendment does not apply by its own terms, and a challenge resting on it alone would fail. Equal protection supplies the correct route. The right to vote is fundamental, and a classification that allocates it by ability to pay is reviewed under strict scrutiny following Harper v. Virginia Board of Elections. The state’s likely justifications — defraying administrative cost, or discouraging casual registration — are not compelling, and cost recovery could be achieved from general revenue without excluding anyone. The fee is unconstitutional, and its modest size is irrelevant: Harper turns on the impermissibility of the criterion, not the magnitude of the sum.

Change one fact. Suppose the statute instead required voters to present a document establishing residence in the precinct, with free documents available on request. Now there is no listed ground and no wealth classification, so neither the amendments nor Harper disposes of the case. The analysis becomes a weighing exercise: the burden imposed on voters against the state’s legitimate interest in confirming eligibility — and a genuinely free and accessible document would very likely survive.

Common mistakes that cost points

Citing the Twenty-fourth Amendment against a state poll tax. It reaches federal elections only; use Harper and equal protection.
Forgetting that the Twenty-sixth Amendment protects citizens aged eighteen and above, not any age classification whatever.
Treating the amendments as general charters over election machinery. They prohibit denial on listed grounds and nothing more.
Analysing districting under the franchise amendments. One person, one vote comes from equal protection.
Overlooking the enforcement clauses when a federal statute regulates state elections. That is where the authority comes from.
Ignoring the congruence-and-proportionality limit. Enforcement legislation must be remedial, not a redefinition of the right.
Pursuing a partisan-gerrymandering claim in federal court after Rucho. Racial gerrymandering claims remain available.
Assuming a small fee is acceptable. Harper condemns the criterion, not the amount.

Frequently asked questions

Are poll taxes in state elections unconstitutional?

Yes, but not because of the Twenty-fourth Amendment, which is limited to federal elections. Harper v. Virginia Board of Elections held that conditioning the franchise on wealth violates the Equal Protection Clause, since voting is fundamental and ability to pay is not a permissible basis for allocating it.

Can Congress regulate state elections?

For the purpose of preventing discrimination in the franchise, yes. The enforcement clauses of the Reconstruction and franchise amendments authorise appropriate legislation reaching state as well as federal elections, which is how the Voting Rights Act operates. The power is remedial and must be congruent and proportional to documented violations.

Where does one person, one vote come from?

From the Equal Protection Clause, not from any franchise amendment. The amendments prohibit exclusion on specified grounds; the requirement that districts contain roughly equal populations, and the doctrine on vote dilution, belong to the fundamental-rights branch of equal protection.

Voting rights in California and Los Angeles County in 2026

The franchise amendments set a federal floor: race, sex, poll taxes and age above eighteen may not be used to deny the vote. California has built well above that floor, and Los Angeles County administers the largest local election system in the United States through the Los Angeles County Registrar-Recorder/County Clerk.

Two California choices matter most. Every registered voter receives a mail ballot automatically, a practice made permanent after the 2020 cycle, and voters may register or correct their registration through election day using conditional registration. Los Angeles County also replaced traditional precincts with a network of multi-day vote centres using ballot marking devices developed by the county itself, a system designed in part to deliver ballots in a large number of languages as federal law requires.

The specifics that decide cases and exam questions:

Parole no longer disqualifies. Proposition 17, approved in 2020, restored voting rights to people on state parole, so in California only current incarceration for a felony suspends the franchise.
Poll taxes and their equivalents are barred. Any charge that operates as a precondition to voting is invalid, which is why identification and documentation requirements are examined closely.
California has no strict photo identification requirement. Signature comparison is the principal verification method for mail ballots, with a statutory cure process.
Pre-registration begins at sixteen. Registration becomes effective automatically at eighteen.
Language assistance is federally mandated here. The county’s multilingual materials reflect obligations under federal voting rights legislation, not merely local preference.
Burdens are weighed, not banned. Neutral regulations are assessed by balancing the burden against the state’s interests rather than by strict scrutiny.

For 2026, confirm current deadlines and vote centre locations with the county registrar before relying on any date. Read with one person, one vote, Section 5 enforcement power and equal protection.

Next steps

These amendments are the textual floor, so read them with the doctrine that does most of the analytical work: the right to vote and one person, one vote covers districting and dilution, and equal protection supplies the scrutiny for every classification the amendments do not name. On the congressional side, the Section 5 enforcement power explains the congruence-and-proportionality limit, and the political question doctrine accounts for why partisan-gerrymandering claims fail in federal court.

The texts of the amendments and annotated commentary are freely available through Justia’s constitutional collection. Cornell’s Legal Information Institute keeps a concise entry with current citations, and candidates should confirm the tested scope against the outlines published by the State Bar of California.