Mr. Macron “now stands as a counterweight to Trump,” Mr. Fried added. The combination of a dominant, seasoned veteran like Ms. Merkel and a young, dynamic newcomer like Mr. Macron, he said, creates an “implicit challenge and perhaps an explicit challenge to the Trump ideology.”
It might be too much to say the French voted to reject Mr. Trump, given the many economic and security issues that confront France and defined the campaign, yet the larger trends he reflected were at stake. “I don’t think it’s a repudiation of Trump,” said Benjamin Haddad, a research fellow at the Hudson Institute in Washington. “I do think it’s a political answer to the challenge of populism.”
The French election followed contests in Austria, where voters rejected the far-right presidential candidate Norbert Hofer in December, and the Netherlands, where the far-right party of Geert Wilders fell short of expectations in parliamentary elections in March.
Mr. Trump had assumed that his own election and Britain’s vote to leave the European Union were harbingers of other establishment dominoes that would fall. “He seemed so convinced coming in that ‘Brexit’ was just the beginning and other countries would be leaving,” said Karen Donfried, president of the German Marshall Fund of the United States. “Clearly, he’s got to correct that assessment.”
Ms. Le Pen had initially sought to capitalize on the momentum from Mr. Trump’s victory in November. She was among the first foreign leaders to congratulate him, and she made an unannounced but highly visible visit to Trump Tower before his inauguration, though she did not see the president-elect. By spring, however, with Mr. Trump highly unpopular in France, she was distancing herself, rarely mentioning him.
Mr. Macron, by contrast, posted a video in February tweaking Mr. Trump by inviting American climate change scientists to move to France since “your new president” is “extremely skeptical about climate change.” In the final days before Sunday’s second-round runoff election, Mr. Macron attempted to persuade his supporters not to take victory for granted by airing an advertisement showing American pundits predicting a decisive election defeat for Mr. Trump.
But Mr. Macron also showed restraint in the final stage of his campaign. For his debate with Ms. Le Pen, his campaign team prepared talking points with plenty of attack lines tying her to Mr. Trump, according to an adviser to Mr. Macron, who asked for anonymity to discuss internal deliberations. Mr. Macron disregarded them. “Instead of scoring cheap points, he went for the more prudent and anticipatory attitude,” the adviser said. “He didn’t want to jeopardize the relationship just for a punch line.”
For his part, Mr. Trump made little secret of his preference in the French contest. After a police officer was killed on the Champs-Élysées in Paris just before the first round of voting, Mr. Trump suggested it would help Ms. Le Pen’s campaign, which focused in part on what she said was the threat of foreigners allowed into France.
“Another terrorist attack in Paris,” he wrote on Twitter. “The people of France will not take much more of this. Will have a big effect on presidential election!”
In case anyone doubted whom he was referring to, Mr. Trump mentioned Ms. Le Pen in a subsequent interview. “I think that it’ll probably help her because she is the strongest on borders and she is the strongest on what’s been going on in France,” he told The Associated Press.
But once the vote was in, he too put aside the election. “Congratulations to Emmanuel Macron on his big win today as the next President of France,” he wrote on Twitter on Sunday. “I look very much forward to working with him!”
One area where Mr. Trump and Mr. Macron may clash is Russia. Mr. Trump has spoken flatteringly of President Vladimir V. Putin and vowed to improve Russian-American relations, but Mr. Macron has taken a tougher line. Mr. Putin hosted Ms. Le Pen in Moscow during the campaign in a virtual endorsement, and the Russian government is suspected in the hacking of the Macron campaign and the leak of documents, an episode that echoed last year’s Russian meddling in the American campaign.
Mr. Trump has made clear he thinks international relations are built in part on his personal chemistry with foreign leaders. If he can put aside his vitriolic attacks on China to forge what he now calls a strong relationship with President Xi Jinping, it seems plausible he could find common ground with Mr. Macron. He could focus on their similarities rather than their differences; neither had been elected before, and each ran against the establishments of the mainstream parties in their countries.
Besides, while Mr. Trump surely would have interpreted a victory by Ms. Le Pen as a validation of his own politics, she would not necessarily have been an easy partner, given that her promises to pull out of NATO and the European Union could have created a less stable situation for the United States.
Still, Mr. Macron, young, diffident and intellectual, is more often compared to President Barack Obama. “He’s sort of the antithesis of Donald Trump,” said Mark Leonard, director of the European Council on Foreign Relations. “He does share this odd thing of running as an outsider when he’s obviously an insider. But I don’t think they could be any further from each other in terms of their ideas, their philosophy.”