Marine Le Pen, the 48-year-old heir to a far-right party once considered beyond the pale in French political life, failed to capture the presidency Sunday night. But she has undeniably broadened the appeal of the National Front and is poised to capitalize on the party’s growing power and play a more authoritative role in opposing the new government.

Le Pen was thwarted by Emmanuel Macron, who won about 66 percent of the vote. He is a former investment banker and Socialist finance minister who, at 39, led an insurgent bid under the banner of a new party to the presidential palace. Together they broke the French political establishment, banishing from the final round the two parties — the Socialists and the Republicans — that have ruled France since 1958.

Le Pen, in brief remarks conceding defeat, claimed the country’s political reorganization as a victory for her and for the populist protest roiling the West.

“The first round led to a major reconfiguration of the French political landscape,” she said. “The second round led to a reconfiguration between patriots and globalists.”

She promised that the National Front would be the “first force of opposition,” although she also acknowledged that her party would have to “renew itself to live up to this moment.”

A supporter of French presidential candidate Marine Le Pen reacts after she was defeated in Sunday’s second round of voting. (Ian Langsdon/European Pressphoto Agency )

This year’s contest marked only the second time that Le Pen’s party, from which she formally distanced herself in a last-ditch effort to win over skeptics, made it to the runoff. In 2002, her father, Jean-Marie Le Pen, who is one of the National Front’s founders and still embodies its roots in anti-Semitism, shocked France by advancing to the second round, only to win just 18 percent of the vote. Fifteen years later, Marine Le Pen — who dates her political consciousness to 1976, when dynamite intended for the family patriarch tore through their Paris apartment — nearly doubled that figure.

Still, the outcome was a stinging setback for Le Pen, who was hoping to ride an apparent populist, anti-establishment wave — beginning in Britain last summer with Brexit and coursing through the United States in the fall with the election of Donald Trump — into power.

Le Pen, who grew up in one of France’s richest districts, proved an imperfect vessel of anti-elite protest, just as the National Front, which has been a fixture of French politics for decades, failed to inoculate itself against its own anti-establishment invective. Looking for alternatives to politics as usual, many voters remained skeptical that Le Pen offered anything but a retreat into the darkest chapters of France’s past, or a leap into a perilous unknown.

“It’s a danger for our democracy,” said Céline Denain, a 32-year-old artist, who pointed to her pregnant belly to explain why a Le Pen presidency was unthinkable to her.

National Front supporters carried plastic blue roses signaling party loyalty to the restaurant and event space on the east side of Paris where Le Pen spoke. They were not surprised by the outcome, they said, and found cause for optimism.

“We are disappointed that she’s not president, but it’s an important score,” said Maurice Blanc, 59, a longtime friend of the Le Pen family. “It’s a score that places the National Front at the forefront of French politics.”

Now, the National Front turns to the June legislative elections, analysts and party leaders said, the aim being to make it impossible for Macron to govern. Le Pen’s party boasts a meager two deputies in the National Assembly but could easily gain the requisite seats, 15, to form an official parliamentary group. This would grant it the capacity to form part of the official opposition to the ruling party, to gain additional speaking time in parliament and to hold more sway in powerful government commissions.

Then there is the question of 2022.

“Too soon to say for now,” said Nonna Mayer, a political scientist at Sciences Po in Paris and an expert on the far right, when asked whether Le Pen would run a third time for president. Mayer enumerated several hurdles, including the June elections, and other regional and local contests, as well as divisions within the movement. Party unity, she said, is threatened by a disagreement between newer followers of the National Front attracted to its doctrine of economic nationalism, a message honed by top aide and party vice president Florian Philippot, and those who crave a harder line on religious and social issues. The latter group sees its views represented by Le Pen’s niece, Marion Maréchal-Le Pen, who may come to pose a leadership challenge to her aunt, Mayer said.

But Christophe Boutin, a political scientist at the University of Caen, said these divisions are overstated. He expects Marine Le Pen to run again in 2022.

“I hope, I hope,” said Marie-Christine Arnautu, a National Front member of the European Parliament and a longtime associate of the Le Pen family, when asked whether the unsuccessful candidate would stand again.

But Arnautu also exemplifies the party’s internal tensions. Sanctioned last year for participating in a rally organized by the exiled Jean-Marie Le Pen, in which he questioned his daughter’s leadership, she represents a wing of the party still wedded to a stricter stance on social issues, such as opposition to same-sex marriage. Marine Le Pen’s promise was economic revival — notably by yanking France from the euro and holding a referendum on an exit from the European Union — not a new offensive in the country’s culture wars.

Arnautu played down these disagreements. She called for unity around the party’s central pledge — saving “the heart of France” from Europe — and predicted that it would gain many seats in the June parliamentary elections, as it welcomed voters fleeing the humbled parties that did not make it past the first round of presidential elections last month.

Growing support for the National Front owes to Le Pen’s efforts, since she took its helm in 2011, to “de-demonize” the party and discipline its message, analysts said. She has sought to present a movement shorn of its ugliest strains, such as denial of the Holocaust; she formally banished her father in 2015. But French media — as recently as last week — have continued to expose Holocaust denial in the highest ranks of the party’s leadership, and despite the purported estrangement between father and daughter, Le Pen ultimately accepted a 6 million euro loan from her father late last year to finance her struggling campaign.

Party members said her electoral gains are the result of years spent cultivating economically dislocated regions of the country, remote from its cosmopolitan urban centers. Dividends came, for instance, in 2014, when the National Front finished first in elections to the European Parliament.

Under Le Pen, the party has made major inroads in once left-leaning parts of the country’s post­industrial northeast, parts of which are now governed by a peculiar patchwork of Socialist and National Front officials. Its traditional base of support has been in the south, where anti-immigrant sentiment is most powerfully felt. But many voters in once-prosperous, midsize towns who have not reaped the rewards of globalized markets have gravitated to the far right, whose leaders promise tightened borders, a new industrial push and protections for workers whose jobs are threatened by globalization.

The phenomenon finds a parallel in Trump’s triumph in the hardest-hit parts of the U.S. Rust Belt.

“For too long, French elites have not resembled the country and its voters,” Bernard Monot, an economist and delegate to the European Parliament representing the National Front, wrote in an email.

With this message, a claim that her movement represents the interests of the underserved majority, Le Pen has steadily sought to move the party into the mainstream. Despite her loss, modest success was evident not just in the percentage of the vote she captured but in the endorsement after the first round of voting of Nicolas Dupont-Aignan, the leader of a rival right-wing, Euroskeptic party.

“She is much more elevated than her father was in 2002,” said Bruno Cautrès, a political scientist at Sciences Po. “Dupont-Aignan presents himself as a Gaullist, and even if it’s a small party, it’s a relationship for the National Front. It shows the party is no longer isolated.”

Yet Sunday’s decisive defeat also suggested that Le Pen’s support may have hit a hard ceiling and that, despite her effort to brush up the party’s image and distance herself from some of her father’s most incendiary rhetoric, the family’s politics remain unacceptable to much of the country. Le Pen gave fresh cause for doubt about the distance between her views and those of her father, a convicted Holocaust denier, when she said last month that France was not responsible for a massive, wartime roundup of Jews in Paris.

“This is not a democratic party; it is a family party,” said Philippe Blacher, a professor of constitutional law at the University of Lyon. “It doesn’t truly evolve. The same lies and insults just come from a new member of the family.”