Outstanding uncertainties about registering, mobilising and verifying voters in today's United States elections show there is no single or optimum way to organise voting, weigh preferences or determine results. Democracy there as elsewhere is a work in progress rather than a perfected system. That needs saying ahead of the next few days of voting, legal challenges and potentially uncertain outcomes - assuming the opinion polls have not misled us all about how close the result will be. They can be misleading in the way they draw samples and reach conclusions from such a large population.
The US presidential election system is an indirect one in which votes are allocated to a national electoral college of state delegates selected according to demographic criteria. This was designed by the Founding Fathers of the US Constitution to protect the political system against the excesses of popular sovereignty and to protect state rights against centralised government. The majority of the popular vote does not determine the outcome, but the requirement to get a majority of 277 votes in the electoral college. Notoriously, they differed in 2000, when Mr Al Gore won the plurality of national votes but lost the election after the Supreme Court declared him the loser in Florida.
That experience has seared this year's contest. This can be seen in the thousands of lawyers assembled by both the main parties at polling stations, in their impressive voter registration campaigns, in the much greater recourse to early or absentee voting on this occasion, in the (still unsatisfactory) refinement of electronic voting machines - and in the uncertainty that pundits and pollsters readily acknowledge is introduced to their analyses by these factors. Newly registered voters are predominantly young, black and poor. They are also much less likely to vote than those who have been registered for longer periods. And yet such voters are more inclined to vote against incumbents than others. All this provides ample material for legal challenge and contestation. We could be waiting longer for a result than four years ago.
Despite the deep polarisation of opinion, the presidential and congressional elections exhibit an extraordinary geographical diversity and regionalisation. Some 26 states, mostly in the interior of the US, are strongly behind Mr Bush or leaning towards him for 222 electoral votes, while Mr Kerry is assumed to have 17 for him, mostly on the coasts, yielding 211 votes. This leaves eight swing states - Florida, Ohio, Nevada, Pennsylvania, Wisconsin, Iowa, Minnesota and New Mexico - in which most of the campaigning has actually been conducted over the last year.
National turnout has been going down because many citizens in "predictable" states do not see the point of voting. A higher turnout on an expanded register is the wild card of the election, with a predicted increase of six percentage points bringing some 60 per cent, or 121 million voters of the eligible population, to the polls.