The US presidential primaries explained

With the US presidential primaries under way, it’s time to find out what all the fuss is about. Why are they so important and how do they work?

The United States presidential primaries are the arena in which the Democratic and Republican parties field their candidates to choose who will be battling for the White House. The primaries have a centuries-old history, though their structure has changed many times over the years, and continues to evolve to this day. The USA’s fifty states plus its overseas territories each hold their own primaries, and each does so differently. This makes for a complex but exciting rollercoaster ride that shuttles the candidates from what is known as primary season, to the party conventions over the summer, national elections in November and finally the much-coveted presidency beginning January the following year.

The US presidential primaries: the basics

Presidential candidates are officially announced at the Democratic and Republican party conventions over the summer. The choice of candidate is made by delegates hailing from each state or territory, who are meant to vote based on the preferences expressed by the electorate in their state or territory’s primary. There are two systems to select delegates, and therefore candidates, for the presidential nomination: caucuses and primaries. Some states use one or the other, and some a mixture of both.

Though the parties’ candidates are nominated officially during the summer, it is likely that their identity will be known by the beginning of June, before the primaries are over. Winning earlier primaries and caucuses means gaining traction for future successes, and a candidate may be assigned enough delegates to win the nomination before primary season ends. Barack Obama, for example, won the Iowan caucus in 2008 and never relinquished his lead to rival Hillary Clinton, even though at the outset he was considered an outsider.

States that vote earlier also influence those coming afterwards because candidates who don’t receive many votes may choose to abandon the race. For example, following this year’s Iowa caucus on the 1st of February, the first primary event, Democrat Martin O’Malley and Republican Mike Huckabee announced they would suspend their campaigns. Not performing well means losing support from voters and donors and being seen by the party as hurting stronger candidates by causing vote dispersal.



State-level party chapters are responsible for organising caucuses. These were the original method for selecting candidates, but the parties have increasingly switched to adopting the primary system.

The word caucus is a Native American term meaning “to gather together and make a noise”. In fact, caucuses are meetings that take place at different tiers of the party structure, from smaller divisions such as wards all the way to the state level. Depending on the state, caucuses can be open or closed: anyone can participate in the former, but only people affiliated to the party can do so in the latter. Typically, delegates are voted for at different party levels and the final decision is made at a state party convention.

Caucuses are often criticised for not being particularly representative of the general electorate. Because participating in the hours-long meetings requires a certain amount of time and dedication, it is only the most politically active – and potentially most radical – party members, including party bosses, who get to vote.



State governments organise primaries, which like national elections take place via secret ballot. These emerged from an early 20th century reform movement that aimed to give citizens more of a voice in the selection of candidates.

There are different types of primaries. In closed ones, a person can vote only in the primary of the party they’re affiliated to. In open primaries, a citizen can express their preference even if they’re not affiliated to the party, though they’re not allowed to participate in both parties’ voting sessions. In semi-open ones, anyone can vote except for a member of the opposing party. In blanket primaries, voters can participate in the election of both parties’ candidates.


Delegates, who can be any party-affiliated US citizen, either express a preference for a specific candidate or are uncommitted. In some states, delegates have to vote for the candidate selected by their state’s voters, in others they don’t.

States assign delegates to candidates differently. In some the winner takes all (WTA): all the party’s delegates in a state will back the candidate who receives the most votes. Other states use proportional representation (PR) in which the number of delegates is assigned in proportion to how many votes a candidate receives. The Democratic Party mostly adopts the latter method. Republicans, instead, allow individual states to choose which system to use.

Democrats also have superdelegates, high-ranking members of the party who aren’t associated with a particular state and can vote according to their personal preferences.

the white house
The primaries are a vital stage in the battle for the White House © Eric Weaver/Flickr

A history of US primaries


When President George Washington decided not to run for a third term, party caucuses in Congress selected John Adams and Thomas Jefferson as nominees.


The choice of candidate moved from intra-party caucuses to national conventions, giving nominees more independence from Congress.


States began experimenting with the primary system, which allowed citizens to elect delegates directly.


New Hampshire became the state that hold its primaries first.


After the 1968 elections, the results of primaries and caucuses became more binding.


Iowa became the first state to elect its presidential nominees. State party bosses had to anticipate the state convention because they couldn’t find an available hotel and so the caucuses were also pushed back and held earlier than New Hampshire’s primaries. State law was changed, dictating that the Iowan caucuses must be the first event in the national primary season – versus New Hampshire’s law, which simply states that its primary must be the first.


21 states held their voting sessions on the same day, which became known as Super Tuesday. The number of states varies from election to election, but it remains the day in which the most states select their candidates. It is usually held on the second Tuesday of March.


Both parties informally agreed that Iowa, New Hampshire, Nevada and South Carolina would hold their primaries in February, with all other states coming afterwards, holding theirs between March and June. This in order to contrast frontloading: when states schedule their primaries earlier, the first four states are forced to anticipate the vote. The parties punish frontloaders by forcing them to give up some of their delegates.

Featured image © Darron Birgenheier/  Flickr

Siamo anche su WhatsApp. Segui il canale ufficiale LifeGate per restare aggiornata, aggiornato sulle ultime notizie e sulle nostre attività.

Licenza Creative Commons
Quest'opera è distribuita con Licenza Creative Commons Attribuzione - Non commerciale - Non opere derivate 4.0 Internazionale.

Related articles