AMNA NAWAZ: Today, France is closer than it's ever been in its modern history to being governed by the far right.

Parliamentary elections that began on Sunday are the country's most consequential in decades and will have implications across Europe and the United States.

Nick Schifrin is here with that story -- Nick.

NICK SCHIFRIN: Amna, the far right National Rally received more than 10 million votes, double the number it has ever received before.

Its longtime leader, Marine Le Pen, celebrated last night.

MARINE LE PEN, President, National Rally Party (through translator): It's a form of great emancipation for the people.

They're taking back their freedom.

They are determined to defend themselves against political powers that have hurt them, that weakened them, that ruined them.

NICK SCHIFRIN: But France's parliamentary elections are two rounds, and, today, Le Pen's opponents, the New Popular Front, a left-wing coalition, and the party of French President Emmanuel Macron could adjust their candidates and still have the possibility of blocking France's first far right government since World War II.

For more on this, we turn to Celia Belin, senior policy fellow at the European Council on Foreign Relations.

Celia Belin, thank you very much.

Welcome to the "News Hour."

Why did the National Rally do so well?

CELIA BELIN, Senior Policy Fellow, European Council on Foreign Relations: It was a foregone conclusion.

When Emmanuel Macron, President Macron, decided to call for a snap election, the National Rally had just come out of a great victory from its European elections.

The reality is that the National Rally has been gaining strength very much over the past two years, mostly because a larger part of France is agreeing on the substance with them.

And then an even larger part of France probably is tired with this government and President Macron himself.

NICK SCHIFRIN: Macron will remain the president, but if National Rally were able to secure a majority and hold the prime ministership and many Cabinet ministers, what would be their platform and what would they be able to accomplish?

CELIA BELIN: So their platform cannot be further from the platform of Emmanuel Macron.

Let me remind you that he's a pro-European, liberal, centrist, versus this National Rally party, Rassemblement National, that is a nationalistic populist in nature, protectionist in nature very much, anti-European, anti-NATO.

And, therefore, the platform that the prime minister is going to push forward, probably some initiatives on immigration, initiatives on purchasing power, will certainly clash very soon with President Macron's own perspectives.

NICK SCHIFRIN: Marine Le Pen inherited what was then the National Front from her father, who was a well-known antisemite who was convicted on racist language.

Is she and her party different from Jean-Marie Le Pen and his party?

CELIA BELIN: They are different in one way.

Marine Le Pen has made the decisions years ago, already 15 years ago, that she wanted to de-demonize her party to make it appear, at least on the surface, like a regular mainstream, albeit radical right, party, but someone that could be in a position to govern at some point.

However, her ideology, the content of her policies, those have not changed.

She's still pushing forwards anti-immigration, anti-foreigner policies.

She's still fundamentally anti-European, anti-American as well, I must say.

Her platform remained this nationalistic populist radical right platform.

NICK SCHIFRIN: Explain the mechanics of what, to Americans, might seem a complex process for this second round.

Could Le Pen and the National Rally still be blocked from a parliamentary majority?

CELIA BELIN: In this election, you can either win in the first round if you are above 50 percent of the vote immediately, or you make it to the second round, which usually is two adversaries fighting each other, sometimes three.

So, if you have three candidates, there's been a call for all forces outside of the far right to make an agreement that the one that's in third position should drop out, so that it becomes a dual, instead of a triangle, because, in a dual, maybe the National Rally is not as strong.

So this will be the conversation of the week.

Who will drop out of the race?

And it's going to be the talk of the week, and it will surely have a strong influence on the results on Sunday.

NICK SCHIFRIN: One of the topics that American officials are most concerned about, of course, is French support for Ukraine and opposition to Russia.

Would the National Rally reduce bilateral French support or perhaps even NATO support for Ukraine or perhaps weaken some of the West's punishments on Russia?

CELIA BELIN: So, for the moment, support for Ukraine is pretty strong in the French population.

And the National Rally will probably stay the course for the moment, because they know how much President Macron cares about it.

They know how much the rest of Europe cares about.

And so it might not be the first fight that they fight.

And they may want to wait out to see whether President Trump makes it back into the White House, and maybe he will be the one imposing a change on Ukraine policy to the transatlantic allies.

And in that case, the far right National Rally will be more than happy to join him into pushing negotiations, lifting sanctions, and eventually maybe even returning to relationships with Russia.

NICK SCHIFRIN: Celia Belin, European Council on Foreign Relations, thank you very much.

CELIA BELIN: Thank you.