The head of France’s Front National, Marine Le Pen, delivers a speech during a meeting in Besancon on Oct. 28 as she supports the far-right party’s top candidate for an upcoming regional election. (Sebastien Bozon/AFP/Getty Images)

After years of shouting from the sidelines of French politics about the dangers of unchecked immigration, open borders and radical Islam, Marine Le Pen had a message this week for the French establishment: I told you so.

“We tried to warn them,” the far-right leader told a crowd of hundreds of cheering supporters in this northern French city, “but we were never heard.”

But after the Nov. 13 attacks that claimed at least 130 lives in Paris and stunned the nation, Le Pen, 47, and her formerly fringe party have found themselves being listened to as never before. Long scorned by the political mainstream as a band of racist xenophobes, the far right in France — and across Europe — is increasingly setting the terms of the post-attack debate.

Since the mass killings gripped Paris, the Socialist government of President François Hollande has borrowed hawkish policies and rhetoric from Le Pen’s playbook. Leaders of the center-right opposition have gone even further.

The idea of a Le Pen presidency in 2017 — once widely regarded as a fantasy — is seen as a real if remote prospect, with her surging National Front expected to take a major step toward legitimacy in regional elections early next month.

What we know so far about who carried out the Paris attacks

“They’re likely to be ruling at least two major regions of France,” said Jean-Yves Camus, an analyst with the French Institute for International and Strategic Affairs. “That would be a huge event.”

The political gains for the far right are not limited to France. Across Europe this year, the twin currents of a poorly managed refugee crisis and a burgeoning terrorism threat have lifted the fortunes of parties that exhibit varying degrees of chest-beating nationalism but are bound by a distaste for immigrants, a suspicion of Muslims and an antipathy toward a European project that for decades has aimed to break down borders and promote continental cohesion.

As in France, such parties have typically inhabited the political margins, with little meaningful influence over policy. But the Paris attacks could propel them into positions of genuine authority — a possibility viewed with alarm by those who fear that the parties’ hard-line prescriptions will play directly into the hands of the very organization that claims to have perpetrated the attacks, the Islamic State.

On the surface at least, the mass killings in Paris seem to validate the far right’s most dire warnings. The attackers were homegrown radicals who were known to authorities, but they still managed to avoid detection while plotting. At least two had traveled to France along the trans-European trail used this year by hundreds of thousands of migrants. One is still on the loose, suspected of having fled to Belgium.

In a thundering speech before supporters in Amiens on Monday evening, Le Pen cited those facts to argue that the country’s political establishment — both the ­center-left and the center-right — was at fault for decades of lax security, misguided openness toward immigrants and “cowardice that made our country vulnerable.”

Hollande, she acknowledged, had been wise to get tough since the killings. But she suggested that the French president has blood on his hands for not embracing her advice sooner.

On Friday, Nov. 13, the worst attacks in Paris since World War II took place. In the days after the terrorist attacks, French authorities responded with domestic raids and a manhunt, and airstrikes overseas. (Monica Akhtar, Deirdra O'Regan/The Washington Post)

The government’s recent moves “are directly inspired by the National Front,” Le Pen boasted. “I simply observe that three weeks ago, the president said they were illusory and impossible. Today they are necessary, urgent and legally possible. In the meantime, 130 people lost their lives.”

Hollande’s response to the latest attacks has been conspicuously harder-edged than was his reaction to attacks in January at the satirical newspaper Charlie Hebdo and at a kosher grocery.

He has wasted no time declaring a state of emergency, then winning approval from the Parliament for a three-month extension that vastly expands the powers of the security services. He also tightened border controls and expanded a bombing campaign against Islamic State strongholds in Syria.

More changes are expected: The government has said it will seek to strip French citizenship from dual nationals who are deemed security threats.

The moves have won favor with the public, boosting Hollande’s once-dismal poll numbers.

“He’s played quite a clever political game” that could help to blunt Le Pen’s appeal by co-opting it, said Anand Menon, a professor of European politics at King’s College London.

Menon also noted that the far right in Europe has, in recent decades at least, run up against “a natural limit to their support.”

But it is unclear whether the usual laws of political gravity apply this time around. “There are signs that the National Front has broken through the glass ceiling, with Le Pen attracting people from both the right and the left,” he said.

She has done that by carefully avoiding some of the extreme language favored by her father, party founder Jean-Marie Le Pen.

After the attacks, he was quoted as advocating a return to the death penalty in France, with the guillotine wheeled out to perform the service. She, however, has been careful not to escalate her rhetoric and instead has merely repeated many of the same demands the National Front has made for years.

Squeezed by the tough language from both Le Pen and Hollande, center-right opposition leader Nicolas Sarkozy — a former president who is seeking to retake the top job in 2017 — has unveiled a series of ever-harsher plans to crack down on immigration, deport terrorism suspects and seal the country’s borders.

Le Pen has long been seen as a favorite to make it to a run-off in the 2017 presidential vote. But until recently, her chances of ultimately winning were dismissed. Now analysts are less sure. “The voter’s main concern now is security,” said Pascal Perrineau, a political scientist at Sciences Po. “The attacks are a game changer.”

And increasingly, politics in France looks like a three-way contest to prove who is toughest on terrorism, a development that has unnerved civil liberties advocates.

Since the attacks, police have used new emergency powers to conduct warrantless searches and place suspects under house arrest. The Interior Ministry said Tuesday that 124 people had been charged under terrorism laws since the state of emergency was imposed.

Pouria Amirshahi, one of only three National Assembly members from the governing Socialist Party to vote against Hollande’s request to extend the state of emergency by three months, said he worried the country was locked with the extremists in a downward spiral that will lead to the abandonment of French values.

“Rather than give in to panic, we must consider another way, and that way is democracy. There’s got to be a path between the National Front and Daesh,” he said, using the Arabic acronym for the Islamic State.

But at the Le Pen rally, supporters had no such concerns. Waving French flags and chanting their leader’s name, they expressed weary relief that after years of being dismissed, their warnings were finally being taken seriously.

They said they just hope that by the time France elects its president in 18 months, voters remember who first rang the alarm.

“Marine is the only real one,” said Lydie Corde, 44, a salesclerk. “The others are just imitators.”

Cléophée Demoustier in Amiens and Virgile Demoustier in Paris contributed to this report.

Read more:

Along the migrant trail, pressure grows to close Europe’s open borders

French far-right leader seeks to reintroduce death penalty after Charlie Hebdo attack

Behind Sweden’s warm welcome for refugees, a backlash is brewing