Transcript for French election will be 'major test' for populism

Sflmplgt that is the scene in Paris today. Tense, heavy police presence as voters head to the polls for the first round of the presidential elections. It is momentous. Our Alex Marquardt is on the scene. Alex, how this turns out today is anyone's bet. Reporter: It really is. It's a beautiful election Sunday here in Paris. These polling stations have been bustling all day. It's fair the say this is the most highly anticipated and potentially disruptive election in recent history. It will be major test for this wave of populism that we have seen sweep across Europe. Much of the focus is on la mean LE pen. She's vowed to crack down on illegal immigration, on islamic extremism. Promised to take France out of the eu and out of nato. And then there's the Russian factor. She's seen as the favorered candidate of Vladimir Putin. It's far from a done deal that she'll go through to the second round. She's among the top four candidates. It's a significant chance. And president trump suggested he thinks that terrorist attack in France just the other day could end up helping marine LE pen. I think people there are thinking even if she gets into the runoff likely would have a much harder time one on one against one of the other candidates? Reporter: Well, security will be major factor in the election no matter what. France is at the highest state of alert because of the terror attacks we have seen over the last 2 1/2 years. Some 50,000 extra forces in the streets today. The big question is whether the terror attack on Thursday that left one policeman dead will change the dynamics. It could. Many experts saying it could help LE pen or Francois fillon. Despite being plagued by a krupgs scandal could be seen as a steadying hand. All eyes on France today. Alex, thank you. Text1 underline

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