PARIS — Everything looks rosy for Emmanuel Macron. He's leapfrogged the scandal-hit François Fillon into second place in the presidential polls; attacks by his rivals haven't dampened his supporters' enthusiasm; and Marine Le Pen has identified him as her main adversary.

But there's still a long way to go until the first round of the presidential election on April 23. And the 39-year-old former economy minister who wants to do away with the old political system is about to realize the very same system can still throw up serious obstacles.

The independent centrist who wants to overcome the old right vs. left divide, which he says is irrelevant and hides the real separation between “progressives” and “conservatives,” faces two dangers, one from each side.

The first, on the right, is if Fillon's rapid fall in the polls, following claims he used public funds to pay his family for allegedly fake jobs, comes to a halt.

The second, on the left, is if Socialist Party candidate Benoît Hamon manages to electrify the party’s hardcore support with his leftist utopian platform based on less work and a universal basic income.

The polls show Macron winning about 20 percent of the vote in the first round of the election, some six points behind far-right leader Le Pen. They predict he would trounce Le Pen in the second round runoff two weeks later, with 63 percent of the vote. But those same surveys make clear the race is far from over.

"Now we will see whether he can make specific proposals without disappointing either his right or his left flank" — Jérôme Fourquet, director at pollster IFOP

Within two weeks, Fillon’s support has dropped from 24 percent to around 18 percent, according to most polls. But it won't get much lower, a member of the Fillon campaign said, because “there’s a core of conservative voters who will never go elsewhere and just want the [conservative Républicains party] candidate to win after five years of [François] Hollande.”

And if polls say 70 percent of the French electorate believe Fillon should drop out of the race, “it also shows you that 30 percent don’t agree with that. Here’s the core we must work on,” said the optimistic Fillon staffer.

As for Hamon, his support surged after he won the Socialist primary by resoundingly defeating former Prime Minister Manuel Valls. Before the primary, Hamon was on 7 percent of the vote. He's now on 15 percent, down from a short-lived high of 17 percent. Post-primary momentum and a platform that overlaps with that of perennial far-left candidate Jean-Luc Mélenchon explain much of that success.

On his left flank, Macron may have to contend with a block of about 25 percent of voters (adding up Hamon and Mélenchon's support) who won't stray far from the Socialist Party, no matter how disappointed they have been with Hollande.

That leaves Macron with a limited pool of voters he can tap into to ensure his presence in the election's runoff.

Meat on the bones

When Macron unveils his detailed policy platform at the end of the month, he may have to “end ambiguity to his own detriment,” said Jérôme Fourquet, director at IFOP, one of France’s main pollsters.

“He has been very good at uniting very diverse segments of the electorate behind him, but so far with general ideas and abstract speeches. Now we will see whether he can make specific proposals without disappointing either his right or his left flank.” At this stage, said Fourquet, the former economy minister has managed to do what no one has done before: be a credible candidate from outside the traditional parties.

Contrary to his rivals’ allegations, Fourquet said, Macron’s voters are not only the young and the well-to-do, and he polls well among the middle-classes and older voters. Where Macron struggles is with blue-collar workers, with only 9 percent saying they are prepared to support him, and lower-level clerical workers, where he polls at around 17 percent.

The real difference between Macron supporters and others, said Fourquet, is their level of education: Only 17 percent of French voters without a high school degree are ready to back him, whereas 39 percent of those with at least two years of college want him as president. He is far ahead of other presidential contenders in the latter category.

His supporters are also the most likely to change their mind before the election. Only 50 percent say they are certain to vote for him. That contrasts with 80 percent of Le Pen supporters who say they are sure they will back her.

“Voter behavior in France remains marked by the historical right-left divide,” said Bruno Cautres, a political scientist at the CEVIPOF research center.

The more specific Macron's proposals are, the higher the risk that he may turn off some of his voters. So far, he has been careful to walk the line between left and right.

He has said, for example, that he will keep the 35-hour work week, a Socialist sacred cow, although he wants to adjust the law to the point where it will no longer mean much. In a similar vein, he has also said he would keep the wealth tax of Socialist lore — although he would limit its tax base to real-estate holdings only.

What could help Macron is his new status as the only sure choice to defeat Le Pen in the runoff.

“We know about the risk that he could look too aggressive on reforms to some and too shy to others,” a Macron aide confided without indicating how his boss would try to solve the riddle, and agreeing with Fourquet that there has been “ambiguity” in his public pronouncements so far.

What could help Macron is his new status as the only sure choice to defeat Le Pen in the runoff.

“In that, he has succeeded at something everyone failed at before, helped by the other guys’ rather bad campaigns,” Fourquet said. “But he would have a much tougher second round if he was facing either a mainstream conservative or a Socialist candidate.”

It seems unlikely Le Pen won't make it to the runoff, however, so for now Macron can focus his efforts on beating his mainstream rivals in the first round.