PARIS — It had seemed inevitable: another face-off in next year’s French presidential election between President Emmanuel Macron and Marine Le Pen, the leader of the rightist, anti-immigrant National Rally Party.
But after nationwide regional elections on Sunday, a rerun of the second round of the 2017 election appeared far less certain as both Mr. Macron’s centrist party, La République en Marche, and Ms. Le Pen’s party failed to win a single one of France’s 13 mainland regions.
The defeat was particularly crushing for Ms. Le Pen. She had portrayed the regional elections as a bellwether of her rise to