Following in his father’s footsteps, Justin Trudeau has beaten the odds to become the youthful, optimistic face of Canada. John Powers sits down with the newly minted prime minister.

An Ottawa River breeze is chilling the air outside Rideau Hall, the grand stone building used for Canadian occasions of state, but on this festive November morning, nobody seems to mind. They’ve come by the thousands to be part of history: the swearing-in of their new prime minister, Justin Trudeau, the 43-year-old son of Pierre Trudeau, who from 1968 to 1984 was the most glamorous PM their country has known.

“This is our Camelot,” the Canadian reporter behind me says, only half kidding. Be that as it may, it’s certainly the triumphant culmination of a strange political journey. “Two years ago, Trudeau was viewed as a lightweight,” says Andrew Coyne, the sharp political columnist from Toronto’s National Post. “Many people would have found the whole idea of him being prime minister funny.”

Yet like so many successful politicians, Trudeau has thrived on being what George W. Bush memorably termed “misunderestimated.” Even as attack ads mocked his callowness—“Justin Trudeau: Just Not Ready”—his upbeat campaign proved him ready enough to win. He led his center-left Liberal Party to a dramatic upset victory over both the far-left New Democratic Party and the ruling Conservatives, headed by the divisive and hard-line Stephen Harper.

Unlike his predecessor, Trudeau celebrates openness and transparency—he plunges into crowds, cheerfully poses for selfies (even at G20 meetings), and shocks some with his public displays of affection toward his wife, Sophie Grégoire-Trudeau. Breaking with precedent, he has invited the public to join the festivities at Rideau Hall, and by the time the wailing bagpipes announce his arrival, among the thousands of people lining his path are several waving photographs and signs that read, “Just in time, Justin!” When the man himself finally pops into view alongside his wife, resplendent in her white baby-alpaca coat, you hear the crowd whoosh with excitement.

It’s easy to see why. Strikingly young and wavy-haired, the new prime minister is dashing in his blue suit and jaunty brown shoes—a stylistic riposte to the old world of boringly black-shoed politicians. To his right is Sophie, whom the New York Post, with characteristic elegance, has termed “the hottest First Lady in the world.” To his left is his much-tabloided mother, Margaret, renowned for partying with the Rolling Stones back in the day. And bounding in merry patterns before them are the couple’s three kids: Xavier James, eight; Ella-Grace Margaret, six; and tiny Hadrien, who’s not quite two. The whole family looks like an advertisement for the Future.