Renaissance spent months languishing in second place in the polls, far behind the National Rally. The top Renaissance candidate, Valérie Hayer, a little-known lawmaker at the European Parliament, left voters cold. The campaign appeared lackluster, and attempts by Mr. Macron to revive it, including through a major speech in April on the future of Europe, backfired.

The National Rally made the election an anti-Macron referendum. It worked.

Mr. Macron has often presented himself as a bulwark against the far right — twice defeating Ms. Le Pen in the 2017 and 2022 presidential elections — and his inability to stem the wave of support for Mr. Bardella on Sunday seems certain to unsettle his remaining supporters. Seven years in office have taken a toll on Mr. Macron, who upended French politics when he burst on the scene to become president at the age of 39.

National political parties run in their respective countries for the European Parliament, but they join like-minded groups once they gain seats. The National Rally is a leading member of Identity and Democracy, a deeply anti-establishment group with hard-line anti-migrant views. Mr. Macron’s Renaissance party is a core member of Renew Europe, a small, liberal group.

In television debates, Mr. Bardella’s opponents liked to point out that he was hardly a diligent legislator at the European Parliament. But little of that criticism seemed to stick with voters, many of whom cared far more about his frontal attack on Mr. Macron than his meager track record in Brussels or Strasbourg, where the European Parliament is headquartered.

In his brief victory speech, Mr. Bardella was measured and firm. “With this historic score for our party, French citizens have expressed their attachment to France, its sovereignty, its identity, its security and its prosperity,” he said, calling on Mr. Macron to rethink immigration policy, protect farmers and defend purchasing power across the country.

“He was impeccable, as usual,” said Nadège Moia, 45, a sales representative who was at the party’s victory gathering in a conference center east of Paris.

Ségolène Le Stradic contributed reporting.