The Fifth Republic is in trouble. This was not meant to happen. De Gaulle established a system with a powerful Presidency at its apex. He and his successors would enjoy executive authority and monarchic prestige. This would enable France to recover from the scars of war and become a country worthy of his exalted plans for its destiny. But the Grenouilles are not easy to rule. When de Gaulle asked how one could possibly govern a nation with 365 different cheeses, he thought that he was joking. His subjects knew better.

Still, things went reasonably well under him and his successor, Georges Pompidou, an unjustly forgotten figure whose reputation would stand higher if he were not overshadowed by the General. In their different ways, his successors have all been inadequate. Vain, shallow and frivolous, Giscard revelled in the trappings of power, but was incapable of exercising it. It would be tempting to say that he was half as clever as he thought. But that would make him a genius.

By the end of his first septennat in 1981, there was no good economic news and no other achievements of note. Still, it was widely assumed – not least by Giscard – that he could not lose. Francois Mitterrand, his challenger, did have a good war – working for Vichy. He was decorated by Petain. Later on, he faked an assassination attempt on himself. It is still not clear how he was able to recover from all that. By 1981, he had re-invented himself as a man of the Left, and proceeded to govern like one. Inheriting a weak position from Giscard, he spent his first two years making it worse. before summoning – of all people – Jacques Delors to restore commonsense. That sort of worked. As President, Mitterrand ordered at least one assassination, a man called Francois de Grossouvre, who undoubtedly knew a lot about corruption in Mitterrand’s circle. It was claimed that he had killed himself. But there was nothing in his medical history to suggest that he was at risk: nothing in his private life or financial affairs to provide grounds for suicide. Moreover, he had a reservation for dinner at a two-rosette restaurant on the day of his death. The suicide was as genuine as Mitterrand’s resistance record. Apropos gastronomy, at least Mitterrand enjoyed ortolans.

Then came Chirac, who also relished the monarchical privileges, who also achieved nothing of substance, and who was also corrupt, After him, Sarkozy, a John Bercow character: President Rumpelstiltskin. There was only one point in his favour. He was not as bad as Francois Hollande, who piled indignity upon incompetence. The French do not begrudge the Presidents their cinq a sept, but not if they arrive on a motor scooter.

So what is next? Until recently, the assumption was that Marine le Pen could not win. Even if – probable – she reached the deuxieme tour, the Left would hold their noses and vote for the Right-winger. Under the slogan “rather a crook than a fascist”, they voted for Chirac against her father.

But Madame Le Pen’s record has been scrutinised, intensely. There is no hint of overt anti-semitism or holocaust denial. She does not wear barbed-wire knickers – and her opponents are flawed. At a time when lots of Frenchmen are suffering from squeezed living standards, Francois Fillon has been exposed as a plunderer of the public purse. In the early Seventies, Jacques Chaban-Delmas, a former Premier with impeccable Resistance credentials, was a Presidential candidate. It was then revealed that he had paid no taxes for several years. A poster appeared. On it, Chaban looked sleek, prosperous, complacent. The words in the bubble were: “Moi, je ne paie pas d’impots. Et toi?” His candidacy was dead. Fillon could suffer a similar fate.

He is unlikely to be given the chance because he is unlikely to reach the final round. Emmanuel Macron is able, young and glamorous: a French Tony Blair. That might sound the ideal profile of the probable victor. In France, that is not necessarily true. The French do no want a Tony Blair. Macron is also a classic member of the elite Parisian bubble. An Énarque, he worked for Rothschild’s. His Left-wing credentials are little better than Mitterrand’s resistance credentials and his private life is fascinating. As his wife is twenty-three years older than him, voters will want to know about his cinq a sept, which is indeed colourful. In the old days, French privacy laws might have rescued him. That was before social media.

It still seems incredible that Marine Le Pen could become President of France. But we live in a world where today’s incredible can become tomorrow’s common-place.