Frida Ghitis is a world affairs columnist for The Miami Herald and World Politics Review, and a former CNN producer and correspondent. The views expressed in this commentary are her own.

St-Remy-de-Provence, France (CNN) Just days before French voters go to the polls, gunshots rang out on Thursday in Paris' iconic Champs-Elysees. It was another jarring reminder to French voters of the high stakes and confusing choices they face in a pivotal election -- one whose outcome has become impossible to predict.

At this moment, there are few details about the killing of a police officer in the heart of Paris , and the motive is unknown, although an ISIS statement claims the shooter was one of its fighters.

It came as the nation focused on the Sunday vote, which will be the first step in electing a new president, a decision that will have repercussions far beyond the shores of France. It will determine if the wave of nationalist populism sweeping across the globe will continue to reshape the international landscape. Or whether perhaps globalization -- a dominant political and economic ideology -- can survive and thrive in the 21st century.

Once the first ballot is counted, we will have a better sense whether the European Union will endure; how Europe is likely to address its refugee issue and what lies ahead for European relations with Russia, after yet another election with signs of meddling from Moscow.

"It's good to have electroshock," Lydia, a local real estate agent, told me. She wouldn't give her last name, but said she will vote for Marine Le Pen, the far-right, anti-immigrant candidate, who seems well positioned to make it to next month's runoff. Lydia said she doesn't expect Le Pen to become president, but she expects a strong showing to give a jolt to the establishment and show the depth of discontent, particularly on the immigration issue.

In storied Provence, a land of vineyards, olive groves and charming towns, it's startling to hear this kind of discontent among the French, but the sentiment is there, and it has already upended French politics. The current President, Francois Hollande, is so unpopular that he decided not to run -- the first president since World War II not to seek re-election.

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And voters are abandoning the two mainstream parties, the Socialists and Republicans, which have dominated French politics for decades. While they have always garnered the overwhelming majority of support, this time they may not get even a quarter of the votes. In fact, the parties that until now took turns governing France may not even have a candidate in the final round.

Voters' dissatisfaction is difficult to understand in a country where the standard of living is among the world's highest . But the reality is that the vast majority say their country is headed in the wrong direction.

The French are distressed by the impact of globalization, a stubbornly sluggish economy, the growing presence of immigrants and refugees and a spate of terrorist attacks by radical Islamists that have killed hundreds and continue to threaten at every turn. Just this week, security forces disrupted what they described as yet another imminent terrorist plot in the city of Marseille.

Incredibly, with just a few days left, almost half the voters I spoke with remain undecided. Even more surprising is the number of people who told me they will not vote at all.

Anjelica Leconte, a 22-year-old student, said "They [politicians] are all liars and hypocrites," explaining why she doesn't plan to vote.

Her boyfriend, Jeremy Entressangle, will vote. But his seemingly contradictory wavering encapsulates the emotional turmoil of the choice. He is leaning toward Marine Le Pen of the National Front, who, as mentioned before, is the far-right candidate, with a disdain for Islam and a fondness for Russia.

But he is also considering Jean-Luc Melenchon, the far-left standard-bearer of the "France Unbowed" Party. Endorsed by the Communist Party, he proposes taxing incomes above $425,000 at 100% , essentially making that the maximum income allowed.

Since Sunday is only the first ballot, the top two candidates will compete in a runoff on May 7. Fears of a runoff between Le Pen and Melenchon have already rattled global markets

But what are the chances these two emerge as the victors? Le Pen has led most of the polls, though surveys show four candidates clustered at the top. Le Pen is followed by the leading centrist in the race, 39-year-old Emmanuel Macron, the center-right Francois Fillon -- who is surviving despite a scandal surrounding government payments to his wife -- and Melenchon, whose meteoric rise in the past few weeks stunned the establishment.

Experts have also warned the French to be skeptical about what they read online amid growing suggestions that Russian media and Russian-linked online operations are working to influence the election. One study showed almost one in five links shared by social media users contained fake news with signs of Russian involvement, favoring pro-Putin candidates. Of the top four, Le Pen appears to have the closest ties with Moscow, but only Macron does not support improved relations with Russia.

And though the outcome of the election is a tossup, the odds appear to slightly favor the young up-and-comer, Macron, who has maintained a steady second, occasionally first, place in the polls.

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Macron, a former economics minister under Hollande, last year founded his own movement, En Marche! roughly meaning "Forward!" The exclamation point gives it a force that some voters told me Macron lacks. He is the standard-bearer of the center, a position from which it is more difficult to stir up fiery passions. He supports the European Union and proposes a hazy blend of economic policies aimed at stimulating the free markets while protecting the country's generous social benefits. And he says accepting refugees fleeing war is the country's duty.