The constitution of the Fifth Republic and the role of its presidency was designed by General De Gaulle for General De Gaulle. For mere mortals the demands of the presidency, the extent of its powers and the mystic relationship between the head of state and the nation have often proved overwhelming. But to political aficionados the election has always held a special fascination. And 2017 looks unlikely to disappoint.

Even before the official campaign season opened, there was a systematic clear out of former Presidents and Prime Ministers. In November 2016, against all odds, Francois Fillon came through to win the Republicans’ nomination (defeating the more favoured candidates ex-Prime Minister Alain Juppé and ex-President Nicolas Sarkozy) and become the hot favourite for the Elysée. This was after all the turn of the conservative right.

But a steady drip of allegations about advantages for his family, and gifts from very ‘generous friends’, have ground to a pulp his carefully constructed reputation for adamantine principles and personal irreproachability. As he, his wife and a political associate now face trials on a number of accounts including embezzlement of public funds, he has turned his fire successively on the media, the judiciary and now the current President all involved in a vast conspiracy to ‘assassinate’ him. Mr Fillon now cuts a pathetic figure, France’s Richard Nixon, wallowing in advanced paranoia, self-pity, recrimination and wrapped in the shroud of victimhood.

Wind back three months and the candidature of Emmanuel Macron appeared quixotic. The fresh faced young Rothschild banker, briefly minister for Economy under François Hollande, never elected to anything, sets up his own political movement (neither left nor right) and puts himself forward as the exemplar of modernity, of innovation, free trade and deregulation. His youthful freshness and enthusiasm struck a chord. He seemed destined to make a good showing: someone to watch for 2022 or 2027. Time was, after all, on his side.

But then the cards fell his way. Not just once, but time after time. Mr Fillon gets mired in this squalid little scandal of self-enrichment. Mr Hollande backs away from the contest. Mr Francois Bayrou, the popular fixture of centrist politics decides not merely not to run but to throw his support behind Mr Macron. And the socialist party rejects Manuel Valls (who now supports Mr Macron), the former premier, who represents the reformist strand of social democracy. He is defeated in the socialist primary by Mr Benoit Hamon, a serial dissident on the far left of the socialist party, the thinking man’s Jeremy Corbyn. Mr Hamon could never compete for the centre ground against Mr Macron. But he has not even managed to unite the left of the left, and now trails – in fifth place – the veteran romantic Mr Jean-Luc Melanchon, supported by sundry communists and Trotskyists. The main political parties of the Fifth Republic appear consigned to history.

In this election season, no predictions have any validity. But just four weeks away from the fourth round, and after these multiple pile-ups, Mr Macron has seen open up not a boulevard heading for 55, Rue du Faubourg St Honoré, but a six-lane motorway. This has become his election to lose. The office held by De Gaulle and Mitterrand could now be won by a winsome thirty nine year old with little experience or preparation for the most important elective office in Europe.

And, from a European point of view, this is a good thing.

What distinguishes Mr Macron from the other leading candidates is his keenness to talk about Europe, his passionate defence of the European Union, his openness to the community method rather than a purely intergovernmental approach, his interest in political innovation, and his pragmatic sense as to how to bring about strengthening the EU. Hence his belief that a revitalised Franco/German relationship is the key; that confidence building between Berlin and Paris including over deficit reduction is the prerequisite to the necessary change in German economic policy; that there are lessons to be learned from having allowed the UK and Poland to dictate the speed of integration; that the EU can no longer only move forward at the speed of the slowest; that a group of countries, focussed on the Euro member states, and including the remaining Big Four, should be the kernel for the next stage.

It is on European policy that Mr Macron shows us the difference. A chasm obviously with Mrs LePen or Mr Melanchon who would both destroy the EU. Or with Mr Fillon whose approach on Europe is tepidly conservative, and strictly intergovernmental. Or indeed with Mr Hamon.

Mr Hamon has moved away from his early euroscepticism. Together with his most stellar supporter, the TV economist, Mr Thomas Piketty, he now looks to a new Treaty or agreement on euro governance. Mr Piketty has devised a complicated formula with a Euroland parliament, made up of national representations (shades of the pre-1979 EP) but including a minority stake from the European Parliament, supposed to provide democratic legitimacy for the Euro. The problem with this idea apart, from the institutional confusion it sows, is that it has zero chance of being accepted by Germany or indeed by some other key euroland states. And the credentials of a France led by Mr Hamon with his eye-watering spending commitments are unlikely to ease acceptance of this new ‘big idea’. A great deal of time would be wasted while the need for cooperation in other areas becomes ever more pressing. Mr Piketty should stick to his day job, and probably will be able so to do.

The election of Emmanuel Macron as President in May would be a turning point in the defence of the European Union, but more widely in support of European values in a cold climate of populism and authoritarianism. Mr Macron would be the candidate least acceptable to the Putins and the Trumps and xenophobes and nationalists of various stripes in different member states.

Those who feel awkward about not supporting the official candidate of their traditional parties and worry about the very light ideological baggage carried by Mr Macron need to think through their priorities.

For European progressives, Mr Macron is the candidate who best embodies our hopes for a revitalised European Union.