The Canadian general election next month was shaping up to be a routine affair, according to some political observers. Drew Fagan, a public policy professor at the University of Toronto, compared the campaign so far to "Seinfeld" — a show about nothing.

But then, this week, Prime Minister Justin Trudeau's re-election campaign was roiled by a scandal over a newly resurfaced photo of him in brownface at an "Arabian Nights" costume party 18 years ago, when he would have been 29, along with a video showing him in blackface makeup.

Trudeau has apologized, telling reporters Thursday afternoon that his behavior was "unacceptable because of the racist history of blackface." But the charismatic 47-year-old, once donned the "North Star" of the free world by Rolling Stone, now faces potentially unprecedented scrutiny in the weeks leading up to the Oct. 21 elections, according to Canadian political analysts.

"There's no question it's damaging," said Fagan, who teaches at the University of Toronto's Munk School of Global Affairs and Public Policy, adding that the scandal could vindicate political foes who find the prime minister "holier than thou, as if he is above reproach."

A 2001 photo shows that Canadian Prime Minister Justin Trudeau wore blackface as part of a costume. Obtained by TIME

None of the political analysts who spoke to NBC News went so far as to predict that Trudeau was headed to defeat at the ballot box. But they said the images severely undercut his public image as a champion of racial diversity and ethnic inclusivity. It also threatens to erode his support with people of color and immigrant communities whose backing helped Trudeau score a decisive electoral victory in 2015.

"In policy, in practice, and in comportment, Trudeau is someone who fights for communities of color," said Peter Loewen, a political science professor who also teaches at the Munk School. "But this scandal could lead many of his supporters to wonder if the prime minister is more talk than action."

In recent years, Trudeau has positioned himself as a paragon of progressivism in the era of President Donald Trump and the ascent of far-right populism in Europe. He has welcomed Syrian refugees, pushed for gender parity in Cabinet positions, legalized assisted suicide and recreational cannabis use, and vowed to tackle gun violence, among other bold rebuttals to the rightward tide through much of the Western world.

Trudeau's liberal credentials are precisely why the offensive images are so "jarring" for his Canadian supporters and admirers worldwide, said Cristine de Clercy, a professor of political science at the University of Western Ontario. But his track record, particularly as an advocate for racial equality and immigrant populations, might also be the very thing that helps him recover from the growing political furor, she added.

Trudeau, whose father, Pierre, was prime minister for 15 years, was already at risk of potential political blowback before the elections because of a separate scandal in his administration: His former attorney general has claimed that Trudeau pressured her to stop prosecuting a top engineering company in Quebec. Trudeau, for his part, insisted he was protecting Canadian jobs — but the appearance of impropriety nonetheless damaged his reputation and reportedly wounded his standing in the polls.

He has also drawn fierce criticism for wearing what some saw as ostentatious Indian garb during an eight-day state visit to India, an appearance that some ridiculed and others labeled insensitive cultural appropriation.

Cecil Foster, a Canadian scholar who has written about the country's multicultural history, said that Trudeau's swift and seemingly genuine apology might help him retain support from his liberal and diverse base, adding that he did not believe there would be "any lasting harm to Trudeau or his election prospects."

But he nonetheless found it curious that a media-savvy, self-styled guardian of progressive values, the son of a leader who helped rally Canada around multiculturalism, would ever think to wear brownface or blackface — a practice that has a painful history in both the United States and Canada.

"We are talking about a young man who, in the eulogy to his father, talked about all the things his father taught him," Foster said. "It is surprising and it is disappointing."

Trudeau mentioned his father, who died in 2000, in his exchange with reporters Thursday, insisting that he strives to uphold the family legacy.

"My father raised me to try and defend people's rights," he said. "My father wouldn't be pleased with how I've behaved, but perhaps would feel that taking responsibility for things is important."