PARIS — The good news, on Sunday night, was that the National Front failed to win any of the 13 French regions. The prospect of seeing the far-right party’s leader, the bellicose Marine Le Pen, as chairwoman of the northern region, or her young equally pugnacious niece, Marion Maréchal-Le Pen, as head of the Provence-Alpes-Côte d’Azur region in the south, had evaporated.  One week earlier, after the first round of regional elections, their party had achieved unprecedented results, reaching 40 percent of the vote in those two regions and scoring a national average of 27.7 percent, ahead of all other parties. On Sunday, French voters rallied to stop them. Many who had stayed away for the first round eventually turned up for the second round.  Because their party tactically withdrew in three crucial regions, Socialist voters gave their votes to right-wing candidates to help the center-right beat the National Front. When the results were announced, a huge sigh of relief could be heard in the mainstream parties’ headquarters, right and left.  Then came the bad news. A stoney-faced Ms. Le Pen refused to concede overall defeat and thanked “the more than six million” French patriots who gave their vote to National Front candidates; late results showed her party had actually gained 800,000 voters in a week. She vowed to fight on.  And she will: Ms. Le Pen is not going away. Her goal is to run for the presidency in 2017, and that has not changed. Shortly before the polls closed on Sunday, an old hand at the National Front told Le Monde that if “neither Marine nor Marion is elected, people will be so enraged that they will make sure we win in 2017.”  Not surprisingly, leaders of the Socialist Party, which won five regions, and the center-right conservative party, Les Républicains, which carried seven, stopped short of claiming victory. (The 13th region is Corsica, where a local party won.) Philippe Richert, from the Alsace branch of Les Républicains, which is the party of former President Nicolas Sarkozy, defeated Ms. Le Pen’s closest adviser in the eastern region, but warned that this election “had shaken the foundations of French political life.”  The former Prime Minister François Fillon, another contender for the presidency in 2017, noted that “the rise of the F.N. has deprived the opposition of a clear victory.”  The governing Socialist Party’s prime minister, Manuel Valls, who came under attack between the two rounds for raising the prospect of a “civil war” in France should the National Front win, insisted that “the danger of the far right is still there.”  Though this election result is anything but glorious for President François Hollande and the Socialist Party, it spells outright disaster for Les Républicains and for Mr. Sarkozy himself. The Socialists have succeeded, at least, in holding a firm line: By instructing their supporters to stop the far-right candidates at all costs — even if that meant voting for Mr. Sarkozy’s conservatives — the political fault line was clear, and their voters acted accordingly.  By allowing Ms. Le Pen to set the agenda, however, Les Républicains have lost their ideological footing. The day after the first round of the elections, on Dec. 6, a desperate Mr. Sarkozy appeared on the evening news, apparently tense and unable to control his nervous tics. He blamed the present government, immigration, the open-border arrangements of the European Union’s Schengen Agreement and “the disappearance of European civilization” — anything but his leadership — for his party’s poor showing.  The man who came back to politics a year ago because he considered himself to be “the best rampart against the National Front” was at a loss to explain why so many of his voters were running away to support Ms. Le Pen and her politics of fear.  Other leaders of Les Républicains have been less charitable. Some of them, like Alain Juppé, another former prime minister who is running for the presidential primaries, have demanded an urgent debate within the party. Leading candidates in the regions, fearful of the effect of Mr. Sarkozy’s divisive tactics, have asked him to stay away from their campaigns. One, Xavier Bertrand, the man who beat Ms. Le Pen in the northern region by uniting the votes against her between the two rounds, even ordered Mr. Sarkozy to “shut up.”  On Sunday night, Mr. Bertrand said that this campaign had “changed forever the way” he was doing politics. A former government minister in Mr. Sarkozy’s administration, he described this election as a “thunderbolt.” He saw it as “the last one before the National Front, maybe, comes to power.” And for that, he blamed “the whole political class,” including himself, for “saying for three decades that it got the message,” while refusing to act. “This is our last chance,” he warned.  The Socialists may be humiliated, but the Républicains are angry, lost and in a state of panic. For the first time since World War II, the xenophobic, euroskeptic far right, which has been steadily growing under Ms. Le Pen’s leadership, has become mainstream.  Where, today, does the right stand in France? What does it stand for? How does it define itself against the anti-immigrant, nativist message of the National Front? What ideology, which strategy will help it regain control of the political agenda before the 2017 presidential election?  These are some of the questions Mr. Sarkozy and his party now have to face. Many bet now, at the top, that the knives are out.  In the United States, moderate Republicans are fretting about the threat that leading presidential candidate Donald J. Trump poses to their party. In France, the destruction is already well underway.  Sylvie Kauffmann is the editorial director and a former editor in chief of Le Monde.  A version of this op-ed appears in print on December 15, 2015, in The International New York Times. Today's Paper|Subscribe
The defeat of the far right in France's regional elections is temporary, unless Sarkozy's party finds a spine.