The new – or maybe the old – French president who is elected today will inherit a country more poisonously divided than at any time since the student and worker revolts of May 1968.
The 45,000,000 French voters face a choice between the soothingly pragmatic leader of a largely unreconstructed left and a President who has appealed shamelessly to the latent nationalist passions and racial prejudices of the French bourgeoisie and white working class.
Although the final opinion polls suggest a four- to seven-point victory for the Socialist challenger, François Hollande, his lead has plunged dramatically in the past six days. President Nicolas Sarkozy, despite his apparent "defeat" in a live TV debate on Wednesday, believes that there will be a "razor's edge" result when polls close at 8pm (7pm BST) tonight.
Mr Hollande insists that this is a European as well as a French election. His victory, he says, would rescue the floundering European Union from its German-imposed obsession with austerity and create new growth and hope through EU-wide capital investment schemes.
Critics say that it might also mark the beginning of a relaxation of fiscal discipline within the eurozone, which would encourage new market speculation and push the euro even closer to the abyss.
At home, a President Hollande would have to manage high unemployment, a high deficit and high debt, despite an unwillingness, on both right and left, to reform an often wasteful French state. But he will also inherit a country that is deeply fractured between a newly radicalised right and an immobile left; between outward-looking cities and anxious and struggling rural areas; and between young and old.
A failed Hollande presidency might open a boulevard for the ultra-nationalist, populist right in France in 2017. A successful Hollande presidency could shift the pattern of European politics towards the centre-left with intriguing implications for Britain and also Germany. How, for instance, would David Cameron vote in Brussels later this year on a Hollande-inspired EU "growth pact", which would run counter to his own austerity-led approach in Britain?
A victory against the odds for President Sarkozy today would also have profound implications beyond the borders of France. In an attempt to seduce the 17.9 per cent who voted far right in the first round of the election last month, the President has campaigned for the restoration of internal EU borders for migrants, and for some trade, but also for the recreation, in effect, of national frontiers of the mind.
In doing so, he has barged though a political frontier that no other French centre-right leader – let alone an incumbent president – has dared to cross since the Second World War. At a time when white-collar populism is rising throughout the EU, Mr Sarkozy has finally abandoned the muddled Europeanism and tolerance that characterised Jacques Chirac's time in office and made scarcely coded appeals to racial and religious intolerance and prejudice.
Some of Mr Sarkozy's campaign rhetoric – insisting falsely that 700 mosques have appealed to Muslims to vote for Mr Hollande – might have come directly from the smear tactics of the French, Dutch or Austrian far right.
The President's official second-round TV message includes a shot of a customs sign, written in French and Arabic. Why Arabic? In the rest of the clip, Mr Sarkozy claims to be the only man who can unite French people of all races and religions. But the entire clip revolves around that brief shot of the customs sign, with its scarcely subliminal message: "I am the man who will stop a Muslim and Arab take-over of France."
If Mr Sarkozy is re-elected after such a campaign, there will be no reason to fear a future tide of intolerant, ultra-nationalist populism in Europe. It will already be here.
It is difficult to say how much of the President's poll recovery in the past week is a direct result of his hardened rhetoric. Few people believed that Mr Hollande would retain all of the 10-point lead that he held after the first round on 22 April. Most French presidential elections are decided by six points or fewer.
But Mr Sarkozy's second-round campaign does seem finally to have reversed the dynamics of an election that until now had been mostly defined by his personal unpopularity on both the left and part of the right.
The new enthusiasm, or tolerance, for the President has come not so much among the 6,400,000 people who voted for the far right and Marine Le Pen on 22 April. The small print of opinion polls suggests that Mr Sarkozy's rise is largely based on a rekindled enthusiasm among his own centre-right voters who failed to turn out in their usual numbers in the first round.
This is partly a tribal reaction in the French bourgeoisie to the looming threat of a Socialist president. But it must also be a response to Mr Sarkozy's rhetoric. Many supporters of the President's Union pour un Mouvement Populaire (UMP) are as intolerant on racial and religious subjects as National Front voters.
In an election campaign in which numbers have been used like truncheons by both sides, there was one especially disturbing statistic between the rounds. More than 60 per cent of voters for Mr Sarkozy's party said they supported political alliances between the centre-right UMP and the far-right National Front.
Former president Jacques Chirac and other centre-right leaders courageously refused such alliances. They also, mostly, refused to use NF themes and rhetoric. Mr Sarkozy is still refusing the alliances but he has hijacked – and in some cases hardened – far-right language on the threat to France's national identity from such menacing enemies as halal meat in school canteens and special hours for women in swimming pools.
He has skilfully exploited Mr Hollande's innocuous plan to give local votes to long-established foreign citizens by suggesting that this will lead to "tribal" control of town halls. As Mr Hollande pointed out in Wednesday's TV debate, there are already millions of French Muslims who have the vote. Why should votes for a few long-established foreigners, not all of them Muslim, make any difference?
It has been a long, and in many ways dispiriting, campaign, on the left as well as on the right. French voters often complain that politicians will not confront the country's real problems. But any politician who has attempted to talk blood, sweat and tears to the electorate in the past three months has struggled in the polls.
President Sarkozy started by suggesting that France should work harder for less, with higher VAT, just like Germany. That did not go down very well. The centrist candidate François Bayrou was the only person to dare to use use words such as "effort" and "pain". He scored less than 10 per cent of the vote on 22 April. On the left, voters have rallied around Mr Hollande's vague programme of fiscal discipline in France and growth programmes for Europe. There will be spending cuts, he says, but he avoids saying where the axe will fall.
Many left-wing voters – more than actually voted for him in the end – preferred the sonorous rhetoric of the protectionist, anti-capitalist, anti-European candidate Jean-Luc Mélenchon. Mr Hollande may well be elected today but he will have no clear mandate for the many tough decisions that lie ahead. If Mr Sarkozy is elected, he will face the task of uniting a country that, thanks to his cynical efforts, is as split as it was in 1944.
Carla vs Valerie
If Valérie Trierweiler becomes "First Girlfiend" with a François Hollande victory today, she will have much to thank Carla Bruni for. The only pop-singing Première Dame in French history has not been a very energetic official consort for the President in the four years since their marriage. But she has changed the unwritten rules of the game.
No French first lady before Bruni has managed to pursue her own career or maintain so successfully a separate public identity. Ms Trierweiler, 46, is a TV and magazine journalist and twice-divorced mother of three. She insists that, if Mr Hollande wins, she will continue to work as TV interviewer.
That would have seemed inappropriate a few years ago. Now it will pass almost without comment. The big question in the French glossy magazines is: "If elected, will François marry Valérie?" There are only 10 days between the election and the handover of power. Ms Trierweiler, an elegant, somewhat frosty-seeming woman, will start off at least as First Girlfriend.
Beyond that, the couple have refused to discuss their plans. Mr Hollande, 57, famously lived for 25 years with Ségolène Royal, the unsuccessful Socialist candidate in 2007. They have four children together but never got married – by her choice rather than his.
Mr Hollande's relationship with Ms Trierweiler began in 2005 but was kept hidden until just after Ms Royal's 2007 defeat. He decided not to run for president that year partly because he feared that the affair with Ms Trierweiler would be exposed. Ms Royal, who knew all about it, ran partly, it is said, to get her own back on her long-time partner.
What kind of person is Valérie Trierweiler? Acquaintances say that her apparent frostiness is a kind of shyness – despite her long experience as a political and cultural interviewer.
The relationship between François and Valérie is very lovey-dovey. Campaign officials reveal that when Valérie phones François on his mobile phone, the screen lights up with the words "mon amour" (my love).
She has been a constant presence in the campaign (far more so than Bruni) but has played no obvious political role. President Sarkozy criticised her presence in March at a memorial service for French paratroopers murdered by the Toulouse killer Mohamed Merah. But Mr Sarkozy offered a public apology when Lionnel Luca, one of the stupider and more right-wing politicians in his party, referred to her last month as "Valérie Rottweiler".