For those of you in the UK who never knew, and those of you in the USA who forgot.

The election for President is usually between two candidates: one Democrat, and one Republican. Except when it isn’t. But let’s just say it is.

That lucky Democrat and that lucky Republican are officially chosen by representatives of each state at the two national conventions in the summer (and these final two then slug it out until election day on 6 November). The conventions are empty prime-time charades of party unity, the actual political debate at which “wouldn’t fill a bumper sticker”, as PJ O’Rourke observed. “Party platforms are as bland as club-soda soup, vague as TV commercials for condoms.” he sighed wearily in Parliament Of Whores.

The real decision-making, hounding, smearing, policy-making and arguing happens during the primary season, when the state representatives for each party are chosen. That’s where it gets interesting – if by ‘interesting’ you mean ‘needlessly complicated’.

This post on The Guardian election blog is a neat summary of the sprawling democratic triffid that is the American primary process. In short, each state holds a primary or a caucus, where voters choose their respective Democrat and Republican nominees. Some states send more representatives to the party convention than others, depending on their size. So California sends 55, while Wyoming sends 3.

The process is spread out over six months, but the vast majority of states will hold their primaries before, or on, 5 February, known as Super Tuesday – and those first frenetic six weeks of 2008 will probably determine which two candidates are vying for President all the way to November.

The primary season commences on 3 January with the Iowa caucus, where – this being a caucus, not a traditional ‘tick the box’ primary – voters gather in small groups in private houses (and schools, churches and community centres) to debate the pro’s and con’s of each candidate, before indicating their preferred candidate by standing in the relevant corner of the living room.

Welcome to America, where Victorian parlour games are used to select the most powerful person in the world.