NEAT mounds of freshly harvested sugar beets await collection on the plains of Picardy. This flat land, around the northern town of Saint-Quentin, is quiet farming country. No refugees are camped out anywhere in sight. No immigrants wrapped in blankets tread the roads. Yet when Marine Le Pen, leader of France’s far-right National Front, takes to the stage for a campaign rally at the town’s municipal theatre, she deplores the “gigantic migratory wave” that is on its way—and the audience erupts with applause.

Europe’s greatest refugee influx in modern history has strengthened right-wing anti-immigration parties from Poland to Switzerland. But the biggest European country in which such a party is close to securing a chunk of electoral power is France. Polls now make Ms Le Pen the favourite to win the region of Nord-Pas-de-Calais-Picardie at two-round elections on December 6th and 13th. Home to nearly 6m people, it covers not only Picardy, the city of Lille, and the mining basin to its south, but also the refugee camp at the port of Calais.

For the National Front (FN), conquering the north of France would mark its biggest victory yet. The party or its allies currently boast two members of parliament, and run 12 town halls. But the movement, founded in 1972 by Jean-Marie Le Pen, Ms Le Pen’s father, has never secured a region. Polls suggest that as many as three are now within its grasp: the north; the region around Provence in the south; and a third towards Alsace in the east. A win in even one would be a big step for a party bent not only on protest, but on power.

Ms Le Pen’s ambition is to transform the FN from a marginalised extremist movement into a serious party of government. She has expelled the thuggish fringe, turfed out her rambunctious father, and recruited policy types to work up wonkish documents. For those packed into the Saint-Quentin theatre, this makes for an odd Saturday night: a mix of crowd-pleasing entertainment (she has a stand-up comic’s timing) and tedious technical pledges. When Ms Le Pen talks about cash-flow problems for small firms, the audience looks blank, and children fidget on their seats. When she vows to end regional subsidies to refugee-aid groups in Calais, however, a huge cheer goes up. Calais, she says, is living “a veritable nightmare” and taxpayers’ money should “serve the French first”. The refugee crisis has played straight to Ms Le Pen’s hand, even though the exodus from Syria and Iraq has headed overwhelmingly to Germany, not France. Traditionally the FN has drawn support from whites in heavily immigrant areas, in the troubled industrial north and the Mediterranean south. But work by Hervé Le Bras, a French geographer, shows that recent gains include places where immigrants are scarce. For many, they need only to see the television images of migrants wading ashore in Greece to swing behind the FN. Mainstream parties seem at a loss as to how to stop this. For the right, tough talk about migrants can sound merely like a pale version of the FN. The left fears that an appeal to France’s history as a land of human rights could push voters into Ms Le Pen’s arms. The FN is already the most popular party among working-class voters: 41% of them back it, next to 24% for the Socialists. The party is even courting Muslims, arguing that the FN is against extremism, not Islam. “Muslim perhaps, but French first” reads one slogan. “Nobody wants Islamism, least of all Muslims,” says Florian Philippot, an FN vice-president. Ms Le Pen’s ascension, however, is due to more than a narrow anti-immigrant message. It is also a pitch to the people against the system. Perhaps the greatest cheers in Saint-Quentin are reserved for her denunciation of the interchangeable ruling parties, which “promised everything” and “betrayed everyone”. They are devoting all their energies not to governing the country, she jokes, but to fretting about the rise of the FN. Manuel Valls, the Socialist prime minister, has warned darkly of the “drama” of a possible FN regional victory, declaring that “everything should be done” to stop it. Yet the more that politicians try to take the moral high ground against Ms Le Pen, the more she casts herself as the victim of an elite cabal.

It may yet be that voters are not ready to hand power to the FN, or that rivals gang up in the second round to thwart it. As Sylvain Crépon, at the University of Tours, points out, even some FN strategists have reservations: the more it accepts the messy compromises of government, the more it “risks losing its radical edge”. As it is, the regions run schools and transport, but have no powers over policing or asylum. So Ms Le Pen’s chief promise over Calais is to “make a din” and force the government to step in, to process genuine asylum-seekers and expel those who are not.

Perhaps the best effort at damaging Ms Le Pen has come from her centre-right rival in the region, Xavier Bertrand, a former labour minister and mayor of Saint-Quentin. For all her anti-system talk, he says, she and her family are in reality “the incarnation of the system,” living for decades “like a vampire” off taxpayers’ money, thanks to the perks of office. His is a sharp point, but it may not be enough. In Saint-Quentin, those queuing up to hear Ms Le Pen do not seem put off. “Even if I don’t agree with all her ideas,” says a middle-aged woman who has turned up with her husband, “she is the only one who speaks about us.”