From a fascinating demographic and political kaleidoscope US voters are forging from this year's primaries one of the most interesting presidential contests in a generation. Super Tuesday has seen Hillary Clinton and Barack Obama fight to a rough draw for Democratic votes, delegates and states.
Their contest will continue towards the summer, pitting his growing momentum against her deepening attraction as the better candidate to deal with a recessionary economy. John McCain has emerged as the virtually certain Republican candidate. He would make a formidable opponent for Mrs Clinton because of his broad appeal. But either Democrat should benefit disproportionately from the extraordinarily high mobilisation of supporters this year.
This national primary revealed how deeply the campaign has penetrated American society, especially among Democratic voters. Initial fears that the ill-feeling shown between Mrs Clinton and Mr Obama in South Carolina would translate into a divisive racial profiling proved unfounded. In addition to his overwhelming black support Mr Obama secured at least 40 per cent of white votes, especially younger ones - and won astonishingly in Alabama. Mrs Clinton, as expected, got most of the Hispanic vote, scoring well too among women, older voters and blue-collar workers. These pluralist results augur well for US democracy; but the temptation to play it dirty will grow until the Democratic outcome is decided, with potentially self-defeating consequences in the presidential contest.
Mr McCain's ability to survive and triumph is equally dramatic. Six months ago he looked finished and then ran out of money. But his dogged refusal to accept defeat carried him through that credibility crisis and added to his appeal compared to the other Republican candidates. Voters have warmed to his long political experience, honest dissent from the Bush administration and passionate commitment to patriotic military virtues, including to the war in Iraq. His moderate record on immigration and abortion enrages the Republicans' reactionary fringe as much as his foreign policy realism antagonises its neo-conservative wing. By the same token independent voters and some swing Democrats can warm to it. Such a profile could be full of surprises next November.
This election year comes at a time of profound change in the United States. Its economic health is in question, its society increasingly unequal and its world leadership role more and more challenged. Within the last year these preoccupations have steadily displaced security, terrorism and the Iraq war from their primary positions as campaign issues. In the process those issues have been reconfigured. The Iraq war is now much more polarising between Republicans and Democrats, while the sheer cost of US military supremacy is increasingly questioned. But Americans' famed ability to reinvent themselves also heartens this invigorating campaign.