Maybe time really does heal all wounds. One of the most surprising moments in Alex Gibney’s new bio-doc of one of the wildest figures in America’s last half-century comes when Sonny Barger, founding member and regular mouthpiece for the Hells Angels, admits that his old nemesis Hunter S. Thompson was “a very good writer.” Even so, Barger says that “doesn’t mean he’s not a jerk in my eyes.”

Jerk, nutjob, genius, drinking buddy, icon — yes, Thompson represented a lot of things to a lot of people. Indeed, he had become a mythic figure well before he died in 2005, having decided it was better to shoot himself than live through George W. Bush’s second term. In his lifetime, his wild-man rep was much enhanced by Bill Murray and Johnny Depp’s respective screen performances in Where the Buffalo Roam and Fear and Loathing in Las Vegas, his cartoon-­ification as Uncle Duke in Garry Trudeau’s comic strip Doonesbury, and his own party-hearty,
gun-crazy habits in his remote Colorado compound.

But Gonzo: The Life and Work of Dr. Hunter S. Thompson — a new documentary by Gibney, the Oscar-winning director of Enron: The Smartest Guys in the Room and Taxi to the Dark Side — does the difficult job of extracting the man from the mythology by concentrating on who he was on the page. Whether Thompson was tangling with bikers, giving birth to Gonzo journalism while stoned out of his gourd at the Kentucky Derby or creating what one campaign official describes here as the “most accurate and least factual account” of George McGovern’s presidential bid in 1972, he was one of the sharpest observers of (and participants in) the various tumults that rocked his country in that era.

“When you see Hunter in that period from 1965 to ’75, he is a man of his moment,” says Gibney in a phone interview last week. “And you need him to understand the moment and you can’t understand him without understanding the moment either — the two are inextricably intertwined. That’s what’s so exciting.”

Capturing the highlights and lowlights of Thompson’s career in a thorough but appropriately freewheeling manner, Gonzo mixes up archival footage with clips from the aforementioned flicks, home movies and interviews with the likes of Barger, McGovern, Rolling Stone publisher Jann Wenner and Depp. (The actor also reads several excerpts from his books. “I think Depp is somehow psychically connected with him now,” says Gibney. “He can channel him.”)

Though the filmmaker says part of the goal was to introduce Thompson and his writing to curious neophytes, he also sought to include enough fresh material to appease the legions of devotees. “We wanted to keep the people who knew Hunter happy,” he says, “even though they might be humming along with a familiar tune from time to time.”

Gibney’s movie occasionally dispenses familiar bromides about America in the ’60s and ’70s, as well as Thompson’s own slide into drug-addled solipsism, which, to be fair, still yielded some wickedly funny writing. Yet it also gives his life story some new urgency by highlighting the “weird and eerie parallels” between his times and our own.

Gibney says it wasn’t his intention to look back and say, “Oh, man, you should’ve been there.” Instead, he hoped to get people thinking about patterns that might link ’72 with ’08. Says Gibney, “We’re about to go into this political campaign where there’s a similar disparity between the two candidates and where a war is at the heart of the matter, and where there seems to be a growing passion amongst young people. There are some parallels that I think are useful. And if you can see Hunter as a man of his time, you can also see how he might apply to the present.”

Furthermore, the movie makes the compelling case that Thompson’s best prose was not fuelled by tequila and mescaline but idealism. “With the later Hunter, you don’t think of the idealism too much,” Gibney admits. “You think of the fireballs and the highballs, and the guns and the angry sense of humour. But I think that really was very present in the young Hunter. Idealism is often a young person’s game, but he really had it. When he was disappointed and wounded, it led to some of his very best writing.”

Since it posits Hunter S. Thompson more as a politically engaged firebrand than an addled madman who liked to shoot typewriters, Gonzo is also not as different from Gibney’s more strictly factual documentaries as it initially appears. Made at much the same time as Taxi to the Dark Side — over which Gibney recently filed a suit against ThinkFilm, blaming the distributor’s financial troubles for his movie’s lacklustre commercial performance despite the Oscar win — the filmmaker says he enjoyed the opportunity to have some fun. And as Gibney says, “Hunter was a guy who liked to have fun.”

Even Sonny Barger can attest to that.