Ottawa, Ontario (CNN) You know him as the man who can break the Internet with a single photo. Canadian Prime Minister Justin Trudeau swept into office in 2015 with a promise of "sunny ways" and "positive politics" for a country feuding over religion, taxes and the military.

But a now series of scandals -- and a new neighbor in the White House -- have ushered in a good dose of gloom.

"He has enjoyed an historic and exceptional honeymoon," pollster Nik Nanos of Nanos Research said. "Now, the shine is off."

With his popularity slipping and the challenges of Donald Trump's administration mounting -- the two leaders are due to meet Monday at the White House -- Trudeau might well be sensing a storm.

Here's how he got to this point:

From bouncer to Prime Minister

His jobs have varied from nightclub bouncer to teacher. A married father of three, Trudeau is an avid athlete who runs, skis, surfs, boxes -- he's even mastered yoga. And from his shirtless encounters with strangers to an official visit with a blushing Catherine Duchess of Cambridge, Trudeau has charmed the world one selfie at a time.

Justin Trudeau, Prince William the Duke of Cambridge, Sophie Gregoire Trudeau and Catherine the Duchess of Cambridge take a walk in Vancouver, on September 25.

Elected to Parliament in 2008, he became Canada's prime minister in November 2015 with a liberal message of inclusion. At age 43, he assumed the office his father, Pierre Trudeau, held decades earlier.

Not so 'sunny': Elbowgate, Castro and chopper rides

The afterglow burned for months. Then came Elbowgate.

It was a jaw-dropping counterpoint to Trudeau's carefully cultivated image of calm. And it was all caught on camera.

In May 2016, while debating a contentious piece of legislation on assisted suicide, Trudeau "manhandled" a member of Parliament and elbowed another, apparently swearing as he went.

JUST WATCHED Opposition: Trudeau "elbowed" female lawmaker Replay More Videos ... MUST WATCH Opposition: Trudeau "elbowed" female lawmaker 02:37

He apologized, twice, and the negative attention was mostly limited to Canada.

No such luck for Trudeau's next misstep.

As the world reacted to the death of Fidel Castro, Trudeau said in a statement that the Cuban leader had been a "larger than life leader who served his people." He left out any mention of Castro's record on human rights and his history of oppression.

JUST WATCHED Trudeau defends his tribute to Castro. Replay More Videos ... MUST WATCH Trudeau defends his tribute to Castro. 01:10

The criticism poured in. #TrudeauEulogies started trending, with mock tributes to despots past and present. In the end, Trudeau agreed that Castro was a dictator.

Even before that ruckus could die down, Trudeau found himself in the middle of yet another scandal. His office confirmed that the Prime Minister spent his winter holiday on the private island of the Aga Khan -- and used the billionaire religious leader's private helicopter to get there. An ethics investigation is underway.

And no sooner had the new year begun than tragedy struck in Quebec City , where a local college student allegedly shot to death six men at a mosque. It was one of the worst attacks to target Muslims in a Western country.

Make Trudeau great again

Trudeau used the massacre to double down on his message of inclusion . "Muslim-Canadians are an important part of our national fabric," he said.

Trudeau speaks during a rally near the Islamic Cultural Center in Quebec City on January 30.

The attack came as Trudeau, aware of his waning popularity and aiming to shed the label of "limousine liberal," embarked on a cross-country town hall road show

He got grilled, heckled and yelled at.

But some commentators saw it as a successful act of contrition after several weeks of damaging missteps.

"That's why he did this incredible tour of the country that no one's ever seen before," said Craig Oliver , chief political commentator for CTV News.

"He's authentic," said Oliver, who has known Trudeau since childhood. "He has real good instincts about people and about politics."

'Sunny ways' still under threat

As he works to dig out of his domestic rut, Trudeau faces new threats to his progressive politics. There's still a strain of nationalist populism that runs deep in Canada.

Oh, and then there's Donald Trump.

Former Vice President Joe Biden suggested weeks before he left office that Trudeau, along with German Chancellor Angela Merkel, would inherit the liberal mantle from former President Barack Obama.

The Trudeaus and the Obamas at the White House on March 10.

"The world's going to spend a lot of time looking to you, Prime Minister, as we see more and more challenges to the liberal international order since the end of World War II," Biden said.

But is Trudeau up to the task?

The Prime Minister is an avowed feminist, free-trader and self-appointed cheerleader for diversity. And just a week before Trump was sworn in, Trudeau issued a thinly veiled swipe at his new American counterpart.

"There are things that we hold dear that the Americans haven't prioritized," he said at a town hall event. "And I'm never going to shy away from standing up for what I believe in -- whether it's proclaiming loudly to the world that I am a feminist, whether it's understanding that immigration is a source of strength for us and Muslim-Canadians are an essential part of the success of our country today and into the future."

After the Trump administration announced its travel ban on seven Muslim-majority countries , Trudeau tweeted, "To those fleeing persecution, terror & war, Canadians will welcome you, regardless of your faith. Diversity is our strength #WelcomeToCanada"

To those fleeing persecution, terror & war, Canadians will welcome you, regardless of your faith. Diversity is our strength #WelcomeToCanada — Justin Trudeau (@JustinTrudeau) January 28, 2017

"Almost everything that Trump represents, Trudeau resents," Oliver said.

Face to face with Trump

As Trudeau preps for his meeting with Trump, some say he should remember the words of his late father, who in the 1960s said that living next to the United States was like "sleeping with an elephant" -- every "twitch and grunt" affects you.

"Agitating the President of the United States is not a good strategy especially when the President is Donald Trump because he has such a thin skin," pollster Nanos said.

Trudeau and Trump are sure to agree on some issues, including support of the Keystone XL Pipeline . But for Trudeau, nearly every facet of his country's economy could be affected by his relationship with Trump.

"There's just so much riding on it," Oliver said. "You know, 75% of Canada's goods are sold in the United States. That border has to stay open for business."

For his part, Trudeau said as much last week during a public appearance ahead of his White House visit.

"We both got elected on commitments to strengthen the middle class and support those working hard to join it," the Prime Minister said. "And that's exactly what we're gonna be focused on in these meetings -- making sure that the millions of good, middle-class jobs on both side of our borders that are dependent on the smooth flow of goods and services and people back and forth across our border are reinforcing the deep connections and friendship between Canada and the United States."