In 1965, the French Fifth Republic went fully presidential: following a constitutional amendment passed three years earlier in a referendum, the Head of State was to be elected by popular vote for the first time. It was widely assumed that General Charles de Gaulle, the incumbent president, would be reelected by a landslide — so much so that he stayed aloof from the campaign.

A very bad calculation, as it turned out: in the first round, de Gaulle garnered only 45 percent of the vote. A TV interview with Michel Droit, a popular conservative anchorman, was hastily arranged and eventually allowed for a 55 percent margin on the second round. One cartoonist, Jacques Faizant, portrayed Marianne — in the French political mythology, the incarnation of the Republic — as a pretty young thing seated on the old General’s knees after a lovers’ quarrel.

“You see,” she was telling him, “this is how you should have talked to me from the very beginning.”

De Gaulle’s days are gone, and Emmanuel Macron, the current president of France, can hardly compare. He might, however, have made the same mistake. Relying on polls that steadily granted him a marked advance on his challengers, and confident that, in a context of pandemics and war, the French would not take chances and were more inclined to reelect a tested president than to experiment with a new one, he almost withdrew from the campaign.

As a result, the outlook of the election was modified. The space he left empty was taken by the Hard Right’s candidate, Marine Le Pen. According to an Ifop poll released on April 6, Macron would get 27 percent of the vote in the first round, coming Sunday, and Marine Le Pen would qualify as his sole opponent in the second round, on April 24, with 23 percent. The final score might then be 53 percent for Monsieur Macron and 47 percent for Madame Le Pen.

Pollsters warn that such narrow margins cannot be accounted for. In other words, anything can happen, including Mme. Le Pen’s victory.

If one is to consider the political families rather than the candidates, the situation is no less awkward. The centrist, moderate camp — the combined votes ascribed to Monsieur Macron and to the classic conservative Valérie Pécresse — gets 36.5 percent. The rightist camp — Mme. Le Pen, Eric Zemmour, and gadfly Nicolas Dupont-Aignan — totals 34 percent. And the Left — now increasingly rallying around Jean-Luc Mélenchon, France’s Jeremy Corbyn — is rising to 27.5 percent.

The truly ominous point is that, unlike what happened in the past, many leftwingers are likely to vote for Le Pen in the second round. Most pollsters opine that 30 percent at least of Monsieur Mélenchon’s voters could switch to Mme. Le Pen. Some even predict a 50 percent switch. Mme. Le Pen herself called them to vote for her in an interview of Europe 1, a mainstream radio channel, on April 6.

The old “defense of the Republic” or “anti-Fascist” imperative that has provided moderates with a substantial last minute reinforcement from the Left ever since the Dreyfus Affair or the 1930’s, and that secured President Jacques Chirac’s reelection in 2002 against Marine’s father, Jean-Marie Le Pen, does not appear to be working any more.

What is emerging instead is a wide Resentment Coalition that pits the “peripheral nation,” Right and Left, against the “elites,” and which, potentially, might attract more than 60 percent of the vote. It does not help saying that such an outcome would be irrational or unethical, or that France is much better off than what rightists and leftists are willing to admit. Resentment is a powerful engine. And once launched, an almost unstoppable one.

Even if Monsieur Macron manages to be elected after all, he will be facing what the French call the  “third round” — the National Assembly’s elections that are to follow almost immediately. It is vital for any president, in any country, to engage with a friendly legislature.

Moreover, the French president would be compelled, under the Fifth Republic constitution, to pick a prime minister and a cabinet from the National Assembly’s majority, a provision that might give him quasi-monarchical powers when the Assembly backs him, or alternatively turn him into a lame duck when it rejects him, as it happened for extensive periods to François Mitterrand and Jacques Chirac.

The issue now is that a narrow Macron victory in the second round would be a near victory for Mme. Le Pen, and might enable the whole Resentment Coalition to enter en masse the National Assembly or even to dominate it. A frightening prospect for the outgoing president — a Red-Black coalition, history suggests, is full of danger for any western country.