The orgy of democracy that has been the 2008 nomination contests has, among other benefits, encouraged a wider appreciation of the diversity of the United States as well as a far better understanding of the American electoral process.

The results of Super Tuesday provided a feast for the army of political nerds - on both sides of the Atlantic - to consume. On the face of it, they imply that John McCain is a strong favourite for the Republican nomination while Hillary Clinton is but narrowly ahead of Barack Obama in the battle to be the Democrat's champion. True enthusiasts for the minutiae of US electoral politics appreciate, however, that matters are, if anything, more complicated than they appear.

1. The Delegate Differential. Not only are the Democrats choosing almost twice as many delegates as their Republican foes (4,049 compared with 2,380) but they select them differently. In most states, Democrats allocate delegates broadly in line with the percentage of votes won. Republicans, on the other hand, tend to reward the victor in a state with either a bonus number of delegates or, in some instances, by handing them all the delegates in that state. Put simply, it is easier for a front-runner to wrap up victory in the Republican competition than the Democratic one. A further complexity is that nearly one fifth of the delegates for the Democrats are not picked by the public but are prominent officeholders. The bulk of these so-called super-delegates are promised to Mrs Clinton today, but there is nothing that prevents them changing their minds.

2. The Caucus Factor. Many of the small states that held ballots on Tuesday decided to hold caucuses not primaries. Caucuses are formal political meetings that occur across a variety of locations and which attract far fewer voters than would come out for a primary. The principal beneficiaries of this facet were Mitt Romney and Mr Obama. Mr Romney “won” the Montana caucus while securing 625 votes in a state where there are 650,000 registered electors. As a result, he got 25 delegates. Mike Huckabee had to win more than 200 times more votes in Arkansas to take almost the same tally of delegates there. Mr Obama stacked up delegates winning three quarters of the vote in places such as Alaska, Idaho and Kansas but with tiny numbers of mostly very liberal sympathisers participating. But the bad news for him is that most caucus states have now voted.

3. The Demographic Distraction. Most of the focus, understandably, has been on how age, gender and race have played out in the nomination races, especially with the Democrats. Yet to a degree this has been a distraction. The biggest single explanation for Mrs Clinton's success has been her hold not over white women but lower-to-middle income white electors and Hispanic voters. On the Republican side, Mr McCain's base is not among older citizens but with self-described moderate Republicans, independents and those conservatives who make “electability” their priority. Ideology, not identity, is what matters here.

The conclusions drawn would be that Mr McCain has an even tighter grip on the Republican contest than it seems and that Mrs Clinton is further ahead of Mr Obama than meets the eye. But, for all the post-poll analysis, this is politics - an art and not a science. There are such unpredictable forces as momentum, charisma and national mood at work. This show will go on.