If Europe's mainstream leaders cooperate with an anti-immigrant, anti-trade President Trump, they will have little choice but to cooperate with far-right politicians at home, politicians and analysts said.
"He reclaimed democracy for the American people," said Geert Wilders, leader of the Dutch far-right Party for Freedom, which is topping opinion polls ahead of March elections. "It can indeed be an enormous incentive in Europe and the Netherlands to see that if people start moving in a certain direction, it can be done," Wilders said in an interview.
Now, he said, national leaders across Europe will have to contend with Trump's ideas - and that means they will also have to engage with European far-right parties that share the same scepticism toward open borders for people and trade.
"They have to take us seriously," he said. "Politics will never be the same again after yesterday. I'm sure about that. It's a kind of new era that we entered."
The cheers began, when French presidential candidate Marine Le Pen was among the first world politicians to congratulate Trump on Twitter, just as he started to pull away in the battleground states.
"They have rejected the status quo," Le Pen, leader of the far-right National Front, said later in the day, vowing to repeat the feat in France. "What happened last night was not the end of the world, it was the end of a world."
Le Pen far outpolls President François Hollande ahead of elections next year, and though it remains unclear whether she can pull off an outright victory, fewer people are ruling it out after the Trump upset. Le Pen has already surged after Isis attacks in France, which were largely perpetrated by French and Belgian citizens whose families had immigrated from North Africa.
"If Isis throws three bombs at Paris between the first and the second round of the elections, then it's Le Pen. They're not stupid," said Ulrike Guérot, director of the Department for European Policy and the Study of Democracy at Austria's Danube University Krems. "You could be really cynical and say the only people who are really united right now in Europe are these people."
That view is shared by many of the far-right leaders themselves.
"This election result gives courage to Germany and Europe, because Trump has the maps for a political turnaround in his hand," said the leader of the anti-immigrant Alternative for Germany party, Frauke Petry, who has been climbing in opinion polls ahead of national elections next year.
Eurosceptic leaders said they would study Trump's freewheeling campaign and seek to replicate it in their own nations. Nigel Farage, a leader of the successful campaign to lead Britain out of the European Union, hit the campaign trail with Trump and plans to fly to the United States tomorrow.
And Dutch politicians say they were inspired by Trump's improvised election effort.
"He has such a small campaign staff, so he relied very heavily on the ground on people in cities, organising things. That kind of civic spirit is something we'd love to take to our campaign. That's something I'm trying to copy," said Thierry Baudet, a Dutch Eurosceptic leader who was one of the organisers of a successful April referendum in which Dutch voters rejected an EU trade agreement with Ukraine.
Austria may be the next country poised to elect a nationalist leader who has many positions on immigration and trade that are similar to Trump's. The anti-immigrant Freedom Party is poised to seize the Austrian presidency December 5 - and it just sent a delegation to the United States to study the Trump campaign, one official said.
But in a hint at some limits on Trump's effect on European politics, the far-right Austrian presidential candidate, Norbert Hofer, took a careful line on the US President-elect, offering him congratulations but little more. Analysts said that domestic anti-Americanism dictated the careful line.
"The overall narrative that we have to stick it to the elites, that the country was usurped by the elite and we need to return it to the people, also works in Austria," said Reinhard Heinisch, head of the political science department at the University of Salzburg.
But "the Freedom Party has to form a coalition, and to form a coalition it has to play well with others," he said.
No matter the local considerations, for many Eurosceptic leaders the Trump victory was a delightful glimpse into future electoral possibilities.
"When it rains in the United States of America, you feel the drops here in Europe," said Filip Dewinter, a leader of Belgium's far-right Flemish Interest party, which has campaigned on an anti-immigration platform. "It will be very tough for the political elite in Europe."
