From his home in northeast France, 24-year-old student Marc was celebrating Donald Trump's stunning success Wednesday.
Not normally involved in American politics, he has been posting messages about "the saviour of the world" for nearly a year on his "French People With Trump" Facebook group, which has more than 1,000 members.
"There's an awakening all over the world, it's an awakening of the nation state, an awakening of the idea of the homeland," the law student told AFP this week from his home in the city of Lille.
Populist political parties and voters like Marc who share Trump's nationalistic anti-foreigner, anti-elite and anti-globalisation views are nothing new on the fringes of European politics.
But the billionaire Republican's stunning breakthrough will give fresh momentum and hope for their efforts to overturn establishment politicians and traditional parties across the continent.
In France, the far-right National Front (FN) founded in 1972 is enjoying record support. Polls show its presidential candidate Marine Le Pen as one of the country's most popular politicians.
Le Pen, whose prospects were being treated with unusual seriousness on Wednesday, was one of the first European political figures to congratulate Trump, describing his election as "good news for France".
In Britain, voters heeded a call to "take their country back" in June when they opted to withdraw from the European Union in a historic rejection of post-World War II integration on the continent.
The day after on a visit to Scotland to promote his golf courses, Trump predicted: "This will not be the last."
A wave of grievances
"Something that has become quite obvious in the Western world is that we are continually underestimating the feelings of frustration and anger among a blue-collar, white and less well-educated section of the electorate," British academic Matthew Goodwin told AFP.
"They feel under the threat of globalisation and are profoundly anxious over ethnic and cultural change," added the expert on the far-right from the London-based think-tank Chatham House.
Across Europe, in countries from Austria to the Netherlands, Germany and even famously tolerant Scandinavia, once-fringe parties are gaining ground and public acceptance.
Trump's upending of American politics is likely to lead to a re-think about how far they can surf the wave of grievances expressed by people famously dismissed as "deplorables" by Hillary Clinton.
"Trump's victory is a sign that the people of the world want a clear political change," Beatrix von Storch, one of the leaders of Germany's insurgent right-wing AfD party, said on Wednesday.
Dutch far-right leader Geert Wilders, an Islamophobic frontrunner in parliamentary elections due next year, told Trump on Twitter that "your victory is historic and for all of us!"
Trump has other admirers in power too, including Hungary's Prime Minister Viktor Orban and the Czech President Milos Zeman.
Dubbed "populists", each group in this network is different but shares characteristics, analysts say.
Their supporters rail against "political correctness". They are likely to live in the countryside or small towns and they see open trade and globalisation as a rigged game for the rich.
Widening inequality and wage stagnation in wealthy countries have fed the anger -- while immigrants are often blamed for taking jobs away from low-skilled native workers.
"Immigration is the single most important vector because it is so culturally visible and so immediately threatening," Jeremy Shapiro, research director of the European Council on Foreign Relations, told AFP.
This has led to a clamour for drawbridges to be pulled up.
In a time of uncertainty, a strong state with secure borders seems the best defence against a fast-changing world. Protectionism is cast as the antidote to decades of globalisation.
John Judis, the author of the recently published book "The Populist Explosion", says that recession, debt and wage stagnation since the global financial crisis of 2007-09 have created fertile ground.
"Once you get a combination of a downturn and rising inequality then you get a lot of resentment directed upwards," he told AFP.
Many observers see the return of nationalism as an inescapable consequence, a direct challenge to the ideological foundations of the European Union.
It could also spell trouble for other international institutions.
Trump made repeated attacks on NATO, the cornerstone of Western military cooperation, dismissed the World Trade Organisation and threatened to walk away from the Paris global climate deal.
EU President Donald Tusk alluded to these dangers in June when he warned that Brexit could unleash forces that lead to the "destruction of not only the EU but also of Western political civilisation."
Conventional wisdom holds that far-right populism should be seen as a warning sign, a trigger for establishment politicians to pay attention to the grievances of an overlooked section of the population.
"Mainstream political parties have responded very late and very poorly to the frustration and anger," concludes Goodwin from Chatham House.
French student Marc wants nothing less than wholesale change.
The political class "is in total denial," he says. "They have an idea of the world which is completely different to ours."