It is a geographical divide that was clearly visible in Sunday's election results, and it could now become Macron's biggest challenge as he tries to win over voters from all sides of the political spectrum.
Polls predict Macron will win by a wide margin over Le Pen in the second round. But there remain several obstacles for Macron.
His strong pro-E.U. position, for instance, is not shared by a majority of French voters. Many left-wingers also blame “arrogant” mainstream politicians like Macron for the rise of the far-right and could refuse to vote for him. That could cost Macron votes in the second round, as could the belief that his victory is almost certain, making it “unnecessary” to go to the polls.
Macron has performed best in urban areas and came in first in many big cities such as Paris, Bordeaux and Lyon. In order to become president, however, he will need to mobilize his supporters to come out in large numbers in two weeks to make up for his weaker performance in many more rural areas.
On Sunday, many young, urban Macron voters appeared remarkably unenthusiastic about their choice. "This was an extremely weird campaign, and I did not know whom to vote for until a few days ago. It’s the first time something like this has happened to me," said Ranain, a 31-year-old who voted for Macron.
At the election night rally of defeated far-leftist candidate Jean-Luc Mélenchon, many said they were planning to abstain from voting in the second round. "Our goal is to change the way our democracy works," said 19-year-old Parisian Zoea Brahams. "Of course I would feel bad if our abstentions lead to a Le Pen presidency, but we simply cannot continue to vote for a candidate we do not like only to prevent the rise of the far-right, as we have done for years now," Brahams said.
Whereas resistance to Macron among some and a lack of enthusiasm among other young voters in big French cities could suppress turnout for Macron, Le Pen's supporters in the northeast and the south of the country see this year's election as a chance to finally have their voices heard.
The country's south has historically been a stronghold of the far-right and in cities like Nice, recent terror attacks have contributed to a further rise of the National Front. In France's northeast, de-industrialization has led to high unemployment rates and a rising support for Le Pen. Economic concerns are on the minds of many voters there, as my colleague James McAuley observed in the town of Hénin-Beaumont on Sunday.
“I feel like I’ve lost a lot of purchasing power with the euro,” said David, 41, who said he worked in financial services. “My salary was much higher when we were on the franc.”
Macron, meanwhile, has enjoyed a particularly high popularity in the west of France, which has historically been predominantly in favor of the mainstream Socialist Party of which Macron used to be a member. As the founder of his own movement, Macron may be able to rely much less on traditional party loyalty among Socialist party voters, however.
All of this is still unlikely to make Marine Le Pen the next French president, but it could make the results much less predictable.
Virgile Demoustier contributed to this report.