Transcript for French presidential candidate Marine Le Pen and Europe's far-right movement
It was a chaotic scene in Paris today as a gunman opened fire on police at one of the city's most popular tourist attractions. The attack coming just days ahead of the heated French presidential election. Now many are wondering if reaction to today's violence could propel a far-right candidate who's been called France's Donald Trump to victory. ABC's chief foreign correspondent Terry Moran takes us on a road trip through a changing Europe. Reporter: One of the most beautiful streets in the world. The iconic champs-elysees on lockdown tonight. A gunman armed with a military-style weapon opening fire. One police officer killed, two others wounded. This man says he saw it all. Within two hours came that claim, that boast of responsibility by ISIS. All this three days before France goes to the polls in the first round of a bitterly contested presidential election. A leading contender in the presidential race, marine LE pen, the candidate everybody's watching. A far-right nationalist with an incendiary anti-immigration argument. This is our home, a rallying cry reminiscent of a familiar refrain. And America heirs! Reporter: The U.S. President today sending his condolences. Eye seen a very, very terrible thing going on in the world today. Reporter: For France, for all of Europe, this is a moment truth. Last month we went on a road trip across these political battlegrounds where the candidates' future will be decided. The big question, has the election of Donald Trump in America and the grim uncertainties of this age of terror emboldened the populist movement around the world, and could the ripple effect mean the end of Europe as we know it? First stop, Paris, the city of lights, now also known for the ever-present reality of terror. We're going to the headquarters of the national front. We're going to go and talk to some of the younger members. So this is where it all happens, right? Why, why sign up with madam LE pen? She's saying like trump did in the U.S., make France great again. She has a strong, really strong message. And she brings hope, more jobs, less immigration. Reporter: Sounds familiar, right? But in Europe, that human tide of refugees from the Middle East has made the immigration issue even more intense. LE pen suggests immigration like this is dangerous, reminding voters of the constant threat of attacks like the massacre in Paris almost two years ago now. We're in a special place. This bar is called labellee keep, the good team. The last time I was here, this was all shuttered. This is where one of the attacks on the horrible night of November 2015 happened. 20 person died here. 10 was in my life. Reporter: Gregory ridenberg was behind the bar when the terrorists opened fire. He cradled his former wife in his arms as she died. But even after experiencing the unimaginable, he is not a supporter of LE pen who he sees as a fearmongerer. I cannot imagine the horror that happened here that night. And for many men, it would have made them angry. You can do nothing with angry, nothing. Reporter: That sounds familiar too. Just like in America. Europeans are in a fierce debate about globalization. And like Donald Trump, marine LE pen is an economic nationalist. So we traveled two hours south to chateauroux to see if she can persuade people here to vote for her. LE pen's campaign is both slick and emotional. Packaged populist anger. Marine LE pen tells a story, a story about how these people here have been ignored by the establishment and that now, through her, they can take their country back. This feels like a lot of the Donald Trump rallies that I covered. It's more than just a political campaign. It's bigger than that. Reporter: And we even saw the parallels to the trump campaign in the crowd itself. This guy with the iconic trump campaign hat. Backstage, we were granted a few moments with LE pen herself. She's brusque, all business. We've seen brexit in Britain. President trump in America. And maybe LE pen in France. How would you describe this political moment? Translator: It's a global movement. In reality it's a rejection of savage globalization, of free trade that's been imposed for decades that benefited very few. If you're elected does that mean the end of the European union? Translator: Eu is a political structure that I find deeply harmful. Think it should cede its place to the nations and to the corporations. Reporter: But a big reason LE pen is popular and feared is her railing against what she sees as islamic fundamentalism and against Muslim women wearing head coverings or veils. She wants to band the so-called bu burkini on French beach. Translator: In reality it's a representation of radical Islam. Women don't want to put on this kind of swimsuit. It's a uniform for radical islamists and radical islamists absolutely will not have a voice in my country. Reporter: Everywhere we traveled, from France to the Netherlands where an election was held last month, we heard the same debate about nationalism and diversity. This is a city that made its wealth, and you can see it here, by being open to the world. It's a merchant city. The question in this election, has there been too much diversity? We need politicians who are not removed from the population. We want real people. Not the socialist rhetoric and . We're sick of it. Reporter: In the Netherlands this guy, wilders often called the Dutch Donald Trump, but voters didn't buy it. He finished a distant second. We had a moment with him while still in the throes of his campaign. You called for the banning of the Koran, closing of mosques. What do you say to people who call that hate speech? I'm not in the habit of banning books but this is a book that is more anti-semitic and more dangerous -- It's the holy book of a billion and more people in the world. It's a book full of hatred, of an ideology that does not want to assimilate. Reporter: Millions of voters across Europe are rallying to that kind of message. Test, France and marine LE pen. With blood on the streets of Paris tonight, her moment may be at hand. For "Nightline," I'm Terry Moran in Paris.
This transcript has been automatically generated and may not be 100% accurate.