Washington (CNN) Sunday's French election result sets up a battle between the heart and the head of the Trump White House.

In the latest blow to establishment party politics in the Western world, two outsider candidates -- centrist Emmanuel Macron and far-right leader Marine Le Pen -- advanced from a crowded field to a run-off for the Elysee Palace on May 7.

Le Pen has risen on the same populist politics, rooted in anger over immigration policies, globalization and middle class economic disenfranchisement, that ignited Donald Trump's presidential campaign last year. She represents a threat to the strength and unity of the political institutions that have underpinned Western countries for the past half century, notably in her opposition to the EU and pledge to leave NATO.

So there's little doubt that the foreign policy establishment types who make up the more conventional, less-populist wing of Trump's national security team will be quietly rooting for the pro-EU Macron in two weeks.

But those sentiments certainly clash with the political DNA of Trumpism.

Le Pen's France-first positions as the head of the National Front mirror the economic and political nationalism of Trump's political philosophy. Like the US president, she plumbed resentment towards elites from a power base in small towns and rural areas that abhor voters in more cosmopolitan, liberal cities.

Le Pen has also for years adopted positions on terrorism, porous national borders and Muslims that often found an echo in last year's US presidential election.

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And while the White House insists that it had no desire to put a finger on the scale of a foreign election, Trump has left little doubt about whom he wanted to win, even if his tweet on Sunday ahead of the results was cryptic: "Very interesting election currently taking place in France."

In an interview with the Associated Press on Friday, Trump noted that the attack that killed a French policeman in Paris last week would have a big impact on the election, and delivered a veiled endorsement of Le Pen.

"She's the strongest on borders and she's the strongest on what's been going on in France," Trump said. "Whoever is the toughest on radical Islamic terrorism, and whoever is the toughest at the borders, will do well in the election."

Le Pen called for "Islamist mosques" to be closed after the attack. Macron was criticized in some quarters for a less hawkish response.

It was not the first time that Trump had sought a parallel with a foreign election. Last year, he frequently boasted that he had predicted that the United Kingdom would vote to leave the European Union.

His comments on France hint at the strong political identification between Trump and members of his inner circle with the goals of European populists.

Two sources told CNN earlier this year that Trump political advisor Steve Bannon told Peter Witting, the German ambassador to the US, that the Trump administration preferred to strengthen bilateral ties with individual European countries rather than deal with the European Union.

In what was described as a "combative" conversation, the sources said Bannon spelled out a nationalist world view and cited a wave of anti-EU populism as evidence of the bloc's flaws, a refrain he had previously articulated as the head of the Breitbart News website.

A victory in the second round of the election by Le Pen would raise the specter of another existential referendum on EU membership.

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The union can survive the decision by the UK, one of its largest but most ambivalent members, to leave. But most analysts believe that the departure of France, along with Germany, one of the key levers of European integration, would spell the end for an institution that has helped consign the continent's blood-soaked past to history.

Given the upheaval in the Middle East and turmoil elsewhere in the world, it's a scenario that few foreign policy experts in Washington welcome.

In fact, some administration officials have gone out of their way during Trump's first 100 days in office to reassure Europeans that they are not rooting for the fracturing of the bloc, despite past rhetoric.

In Brussels in February, Vice President Mike Pence expressed the "strong commitment" of the United States to continue to work in "partnership" with the European Union.

Any weakening of NATO, meanwhile -- which Le Pen has vowed to leave if she becomes president -- would certainly threaten US global influence and ultimately raise questions about Western security.

Le Pen has gone so far as to chide Trump for what she sees as a reversal on NATO, a body that he criticized during his campaign but has now embraced.

"Undeniably he is in contradiction with the commitments he had made," Le Pen said in an interview with France Info radio last weekend.

Many foreign policy experts in Washington believe that a weakened NATO and European Union would directly aid the goals of Russian President Vladimir Putin.

Le Pen visited Putin in Moscow in March and, like Trump, used her campaign to call for better relations with Russia.

Macron is a far less confrontational politician than Le Pen. Given his relative inexperience and euphoric rallies, he drew some comparisons to Barack Obama in 2008. (The former president called Macron last week to wish him luck).

While he has chosen to form his own party and not stand as part of the establishment, he is nothing if not a member of the French elite.

Although the former banker has never held elective office, he once served as a French finance minister and attended the top Paris schools that mold future establishment leaders.

If, as most analysts expect, he emerges as the winner of the second round of the election, he will face the task of forging relations with Trump, a politician who temperamentally and philosophically has more in common with Le Pen.