5.1, 5.1.1 - Presidential and congressional elections

Eligibility and the invisible primary

A candidate must satisfy constitutional rules before political popularity can produce a presidency. Article II requires a natural-born US citizen, aged at least 35, with 14 years of US residence. The Twenty-second Amendment normally prevents election to the presidency more than twice. A person who has served more than two years of another president's term can subsequently be elected only once. These are legal qualifications, not guarantees of nomination or victory.

During this early contest, a candidate builds an organisation that can survive the formal contests. A governor's endorsement might provide local volunteers; donations can pay organisers and advertising; favourable coverage can persuade further donors that a candidacy is viable. These resources reinforce one another. A candidate who cannot raise money or attract support may withdraw before any primary votes are cast, narrowing the choice voters later receive.

Calling the stage invisible does not mean it is secret. Debates, announcements, polling and endorsements are often public. It means that no official national ballot records its winner. Party elites can influence the available field, but cannot simply assume that their favourite will win: Donald Trump's 2016 nomination showed that a candidate can overcome opposition from prominent figures within a party. Treat endorsements and fundraising as resources that improve a candidate's position, rather than as votes that legally choose the nominee.

The US government guide to candidate requirements identifies the constitutional conditions separately from FEC registration. The distinction matters: campaign registration regulates the campaign's financial activity; it does not award a nomination.

Primaries and caucuses

The formal nomination contest is a series of state and party contests rather than one national election. A primary generally uses a secret ballot to record voters' preferences. A caucus is a party meeting; its procedure may involve discussion, grouping or a ballot. A caucus is therefore not always an open show of hands. Both feed into the selection and allocation of delegates who represent the state party at its national convention.

An open primary allows participation without registration as a member of the party holding it. A closed primary restricts participation to registered party voters. Intermediate arrangements also exist. Open rules can broaden participation and admit independents; closed rules give party identifiers greater control over the party's nominee. Neither label tells us the eventual turnout or the candidate's ideology on its own.

Delegates are allocated under the particular party's rules. Democratic presidential contests generally use proportional allocation with a qualifying threshold; Republican rules can include proportional, winner-take-all and mixed arrangements. Winning 51% of a primary vote does not automatically mean receiving 51% of that state's delegates, and presidential nomination rules must not be confused with Electoral College rules.

The calendar also changes incentives. Early contests receive disproportionate attention because their results can establish or destroy a claim to viability. A small early victory may generate coverage and donations that help a candidate compete in later, larger states. Conversely, a poor start can cause donors to leave. Later voters can still matter when the contest remains close, and early-state success is not a constitutional condition for nomination.

The USAGov account of primaries and caucuses, updated in February 2026, emphasises that state and party rules vary. This is useful evidence against the misleading claim that every US voter takes part in the same nomination procedure.

National party conventions

National party conventions give a nomination contest a formal party conclusion. Delegates vote to nominate the presidential candidate under party rules, the vice-presidential nomination is confirmed, and a platform sets out the party's policy commitments. A nominee usually arrives with sufficient delegate support already secured, so the event commonly presents an agreed ticket rather than choosing among equally viable contenders on live television.

Conventions still have political functions when the nomination is settled. Speeches display unity after an internal contest, introduce the ticket to a national audience and frame the general-election campaign. Negotiation over the platform can give losing factions a reason to support the winner. A nomination ceremony can build enthusiasm, although an immediate polling improvement is not proof that the convention determines the November result.

If no candidate commands the required delegate majority, further ballots and negotiation can matter. Bound delegates and unpledged delegates operate under rules that differ between the parties. In the Democratic Party, superdelegates are not simply free to overturn a contested first ballot: the current rules restrict their participation at that stage. Do not memorise a universal delegate rule for both parties.

The 2024 Democratic nomination also illustrates why the typical sequence is not an inflexible constitutional script. Joe Biden withdrew after the state contests, and Kamala Harris secured the nomination through the party's subsequent delegate process. The mechanism was a party nomination, not a second presidential general election. Party rules resolve the nominee; the Constitution governs election to the presidency.

The US government convention guide explains both the usual confirmation of a majority-backed candidate and the possibility of repeated balloting. Reading both prevents two opposite errors: dismissing conventions as legally meaningless, or treating every convention as an unpredictable open contest.