FAQ: The Us Primaries

What are the primaries?

Primary season is the first round of voting in the US presidential election. Rival candidates to win the Republican and Democratic parties' nomination to run for president face off against each other in a series of state-by-state contests known as primaries or caucuses.

The Iowa caucuses were held last night. Next on the calendar are the New Hampshire primaries next week, followed by contests in Nevada, South Carolina and Florida.

What is a primary? What is a caucus?

A primary is a state-wide ballot, held much the same as any other election. The differences are in who is permitted to take part: in a closed primary participation is limited to a parties' registered voters (voters can choose to register as supporters of either party, without becoming fee-paying members in the British sense); in an open primary, voters with no party affiliation, known as independents, can also take part.

A caucus is a more complex affair - a local meeting spread over several hours where Republican and Democratic voters (they can register a preference on the door) meet to speak up for their candidate, in full view of family, neighbors and friends before the vote takes place. The dynamics of the hall can have an impact on the final winner, as the rival camps battle to bring participants to their corner.

Who chooses whether a state holds a primary or a caucus?

The states themselves. The rules for caucusing, the less prevalent of the two, can also vary from state to state and - as in Iowa - from party to party, where the Democrats run a two-round process. Some states hold a third type of contest, a party-run primary, which can also be called a caucus despite having little in common with Iowa-style meetings.

How is the over winner decided?

A candidate's progress through the season is measured in the number of delegates he or she collects from each contest for the late summer nominating conventions. Delegates are usually awarded on the basis of a candidate's share of the vote (a few contests are non-binding and use other methods to allocate delegates - again it varies from state to state). The nomination is usually settled within a few months of the first vote when a clear front runner emerges and the remaining candidates in the race concede. The most likely date in 2008 is February 5, when delegates from more than 20 states are up for grabs, including populous and delegate-rich New York, California and Illinois.

Primaries and caucuses continue through the spring and early summer up to as late as June, but will only have an impact if there is not already a clear winner. If the late primaries fail to produce to a nominee, the process then moves to the nominating conventions - however, this has not happened since the 1970s. Which states are the most important?

More populous states have more delegates to win, but the aura around an individual contest and its place on the calendar can be more important. Relatively small Iowa and New Hampshire absorb huge amounts of money and the candidates' time because their status at the start of the process (which both states actively protect) is imbued with the potential to give a winner or high achiever the momentum to move forward.

This was true for John Kerry in 2004, who won both states (becoming near-invincible) but not for Bill Clinton in 1992, who lost them both. Upsets and surprises are historically more usual in the early primary season than Kerry-like clear runs. George Bush won Iowa in 2000 but lost New Hampshire to John McCain, setting up a contest in South Carolina now remembered for its negative campaigning and dirty tricks.

One rule of thumb is that until a clear winner emerges, the next primary is always the most important. It may be the one the settles the race.

2008, however, introduces a new element - the biggest-ever Super Tuesday on February 5, when a record number of delegates are up for grabs, including in states such as New York and California that usually hold primaries after the nomination race is over (and therefore lack influence on it).

The former mayor of New York, Rudy Giuliani, has gambled that it allows him to ignore the orthodoxy of winning in early, often small, states and fight for big wins in big population areas. It remains to be seen whether he was right.

The presidential election is in November. Why are the primaries now?

The primary season has been slowly creeping forward and becoming more compressed since the 1970s when voters in the states replaced the party conventions as the power behind the nomination. For the 1972 and 1976 elections, the primaries started slowly allowing, for example, an outsider like Jimmy Carter to build momentum and campaign fighting funds.

Soon after, states sought to increase their influence in the nominating calendar by moving their primaries forward. Attempts by the parties to limit the sprawl of early voting states by imposing a March and now February firebreak on the rest created the Super Tuesday phenomenon. However, not all state parties accept this and 2008 sees a number of primaries held without the backing of the parties' national committees - including Florida's on January 29. Flordia's Democratic party has been told it can send no delegates to the Denver nominating convention, while the state's Republicans have cut the state's allocation by half.