The results in the California primary will depend to a considerable degree on the results of the contests that precede it.

PRIMARY INFORMATION Date of primary: 5 February [Super Tuesday] Election polltracker Full state profile Q&A: US primary elections

For the Republicans, polls suggest that Rudy Giuliani has lost his lead here, with John McCain now the front-runner in the state. If Mitt Romney is able to build up momentum in the race, however, then he could challenge Mr McCain and stage a repeat of his victory in neighbouring Nevada.

The Hispanic community could be crucial in the Democratic race in California, and Hillary Clinton showed in Nevada that she is popular with Latino voters.

Mrs Clinton currently holds a lead over her nearest rival, Barack Obama, but Mr Obama's wins in Iowa and South Carolina could give him some momentum going into the California contest, allowing him to win a number of delegates here, even if Mrs Clinton wins the state-wide vote.

Although the California primary is much earlier in the timetable than in previous years, candidates have still been unwilling to spend money in the state, preferring - as is usually the case - to take money from California's many rich donors.

California is the most populous and wealthiest state in the US, and although they have a reputation for social liberalism, Californian voters usually favour fiscally conservative economic policies.