Paul Durand/EPA Opinion Marine Le Pen has already won The ideology of the National Front has already shifted the debate in France.

OXFORD, England — If the French commentariat is to be believed, Marine Le Pen has already lost. The leader of the far-right National Front party might be one the front-runners in this week’s presidential election, but she’s thought to have little chance of winning the decisive second round on May 7.

And so, few are grappling with the fact that her party — once considered beyond the pale — has become one of the most popular in the country. It’s almost as if her defeat has already been digested and business as usual can resume.

The truth is far more alarming. To begin with, it is not at all certain that Le Pen will lose; how voters behave in runoffs is notoriously difficult to predict. And even if she does, she will nonetheless emerge as one of the election’s winners.

Le Pen will almost certainly secure record levels of support in 2017, having made spectacular progress in parts of France that have been traditionally lukewarm toward her party (such as Brittany) and among workers, inhabitants of provincial and rural France, women, and first-time voters. Millions will have embraced the Front’s authoritarian, inegalitarian and intolerant vision of Frenchness.

More important still, Le Pen is winning the battle of ideas, as her party shapes mainstream attitudes on a range of central issues.

Take immigration: A majority of French people share the Front’s view that their country has too many immigrants and should refrain from admitting more. As a result, the French government allowed in only a modest number of refugees from Syria — in notable contrast with Germany. Discussion of the subject has become a political taboo; it has not featured at all during the campaign.

The Front’s audience has also grown thanks to the tacit support of conservative nationalist publicists who disseminate many of its key ideas in the press.

Likewise, on the sensitive question of the place of Islam in French society, the Front’s deliberate conflation of the peaceful religion of the vast majority of French Muslims with “Islamism” (the destructive ideology of jihadi groups) has contributed to a growing intolerance towards followers of the faith.

The party has also helped promote an aggressive form of secularism, one that often stigmatizes Muslims and seeks to regulate their social and cultural freedoms. A 2016 poll found that a majority of French people now believe that Islam is “incompatible with the values of the Republic.”

The Front’s ability to shape public opinion has been facilitated by its astute use of social media (Le Pen’s Facebook site has more than 1.2 million followers, more than any other French politician) but also its institutional normalization. Appearances by Le Pen on radio and television are commonplace, and only rarely are her policies seriously challenged by France’s complacent broadcasters.

The Front’s audience has also grown thanks to the tacit support of conservative nationalist publicists who disseminate many of its key ideas in the press and in best-selling pamphlets such as Alain Finkielkraut’s L’identité malheureuse and Eric Zemmour’s Le suicide français. Neither of these authors is formally affiliated with the party, but their ideology of a closed and pessimistic nationalism broadly overlaps with Le Pen’s.

The common overarching theme is the notion of a “French decline” — internationally (France’s emasculation by Anglo-Saxon dominance), politically (the national elites’ failure to defend France from globalization), culturally (the erosion of French intellectual influence) and socially (the dispossession of French “national identity” by multiculturalism and cosmopolitanism).

This closed nationalist ideology embraces a myopic vision of the past, celebrating French imperial and colonial grandeur while rejecting attempts by historians to shed light on the murkier episodes of the nation’s history.

It is in the name of opposition to such “repentance” that Le Pen controversially absolved France from responsibility for the deportation of Jews by the Vichy regime during the World War II. Widely portrayed as a gaffe, the provocative statement was in fact a deliberate signal to cultural conservatives that Le Pen wants to make France great again — even at the cost of historical truth.

Seven out of 10 Republican voters now believe that Le Pen’s movement is a “party like any other.”

If Le Pen makes it to the second round, all of these gains will come into play. Her populist rhetoric regarding the corruption and elitism of French politicians will also hit home, especially if she faces François Fillon, the embattled Republican candidate dogged by accusations of financial impropriety.

Indeed, it is a measure of Fillon’s weakness that he is increasingly borrowing dog-whistle expressions from the Front’s playbook, notably when he champions “French identity” or condemns “anti-French racism” — a direct echo of the Front’s (entirely unsubstantiated) claim that the welfare system is systematically exploited by immigrants to the detriment of white French citizens.

Crucially, the notion that the Front is a “normal” political movement has made significant headway among right-wing voters: Seven out of 10 Republican voters now believe that Le Pen’s movement is a “party like any other.”

At an electoral rally in late February in Nantes, Le Pen described the dissemination of her ideas as an “accomplished ideological victory.” The skepticism with which her claim was met only makes it more likely that she’ll ultimately be proved right. Unless her success in reshaping French opinion is confronted, she could well end up having the last laugh.

Sudhir Hazareesingh is a fellow in politics at Balliol College, Oxford and the author of “How the French think: an affectionate portrait of an intellectual people.”