PARIS — Could Marine Le Pen become France's next president?

A quick look at polling trends suggests that at first blush at least, the answer is "no." While the far-right National Front leader looks certain to make it through the presidential election's first round, all surveys show her losing in the second, regardless of whether she is facing centrist Emmanuel Macron or conservative François Fillon.

But for Serge Galam, a French physicist who predicted Donald Trump's election in the United States, polls are missing out on an important factor: abstention — and specifically, how it affects voter turnout for different candidates. He argues that abstention, which a poll by CEVIPOF showed could be as high as 30 percent, is likely to be decisive in a "dirty" campaign dominated by scandals.

"Obviously, nothing is done yet but her election is becoming very likely," said Galam, a researcher with the French National Center for Scientific Research who also studies public opinion at the CEVIPOF political science institute. "I'm taking a scientific view of this — she needs a turnout differential of about 20 percent to win."

The road to the palace

In a chat with POLITICO, Galam explained how his model works for different election scenarios.

The National Front leader could benefit because a substantial number of people who say they will vote for her rival may not actually go to the polls.

If Le Pen is projected to lose the runoff by 41 to 59 percent, for example, Galam argues that Le Pen could still win if the turnout rate for her voters is 90 percent versus 70 percent for her rival, for an overall turnout rate of 79 percent. In other words, the National Front leader could benefit because a substantial number of people who say they will vote for her rival may not actually go to the polls.

Equally, if Le Pen is projected to lose by 45 to 55 percent in the runoff, she could win if turnout for her is 85 percent versus 70 percent for her rival, for an overall turnout of 77 percent. If overall turnout is 76 percent, then Le Pen would need a turnout of 90 percent versus 65 percent for her rival, and so on.

Some polls have Le Pen lagging behind Macron or Fillon by more than 30 percentage points, which would make her victory near impossible. But others show her within striking distance, with a lag of less than 20 points. If she can shrink the gap, then the challenge for Le Pen will be to mobilize a greater proportion of her supporters than her rivals.

In this regard, Galam argues that Le Pen has a shot. For different reasons, he says, both Macron and Fillon aroused intense feelings of "aversion" among some voters, with a large proportion of Macron voters saying they could change their mind on election day. Negative or ambivalent feelings could translate into weaker turnout for them on election day.

Indeed, in order to beat Le Pen, Fillon and Macron both rely on the assumption that a broad cross-section of voters will rally behind them in the election's final round, according to a tactical voting principle known as the "Republican front." That principle was influential in 2002 when voters handed Jacques Chirac the presidency over Jean-Marie Le Pen, Marine's father. In less dramatic fashion, it also stopped Marine Le Pen and her niece, Marion Maréchal-Le Pen, from winning major regional seats in a 2015 election.

This time is different

With scandals dominating news coverage and Fillon defending a "Thatcherite" economic program, many left-wing voters could balk at backing him in the final round against Le Pen, Galam said. Conversely, many conservative voters could refrain from backing Macron because they see him as a natural heir to Socialist President François Hollande, whom they detest. In each case, the second round "Republican Front" principle might come into play but not as powerfully or decisively as in the past.

Le Pen, by contrast, might benefit from a more motivated voter base.

"Whether it's Fillon or Macron, a big number of voters in the other camp are going to be paralyzed, even if the alternative is Marine Le Pen," he said.

Galam's idea of the aversion factor is based on "what I see and hear around me," he said. "I am not making a prediction or saying this is definitely going to happen. What I'm pointing out is that there is an enormous zone where Le Pen wins," despite polling at less than 50 percent.

"The polls show this: People who want to vote for Marine Le Pen are going to vote for her" — Serge Galam

"The polls show this: People who want to vote for Marine Le Pen are going to vote for her. And a lot of people will vote against her, but in that group, there is a lot of reticence," he added. "I just argue that we should be realistic about abstention and the role it's likely to play."

'Hard-headed' French voters

If Galam's prediction is getting attention, it's partly because he correctly called Trump's election victory during the summer of 2016. However, he is quick to point out that the method he used to predict Trump's win is not the same as the one he is using for Le Pen.

To consider Trump's chances, Galam developed a complex model combining methods from physics and statistical sociology. It revolved around the ideas of critical thresholds or tipping points in public opinion.

Often by exploiting prejudicial views, Trump was able to break through certain resistance levels in terms of support by generating a critical mass of discussion between voters, many of whom were undecided, Galam argued.

In France, this works less well because voters are less fickle or, to borrow his expression, are more "hard-headed." They tend to know who they like or not as a candidate.

"My approach for the [National Front] is different," he said. "The pollsters are looking at transfers of votes, who benefits where. It's all rather complex. What I'm doing is blindingly obvious: I just start from the principle that a voting intention is not the same thing as an actual vote, and work from there."