SALT LAKE CITY — IT’S hard to imagine anything more painful than going through the presidential campaign all over again with Mitt Romney.

Unless it’s going through two presidential campaigns with Mitt Romney.

But, yes, that’s the narrative of a new buzzed-about documentary that had its world premiere here on Friday night at the Sundance Film Festival.

Those who have seen “Mitt” — which debuts on Netflix on Friday — are agog that filmmaker Greg Whiteley has accomplished what Romney himself, the gleaming, ever-replicating Romney clan and the candidate’s high-priced political strategists could not: Willard Mitt Romney seems all too human.

He wells up. He prays with his family, kneeling on the floor of hotel rooms, and plays with them in the snow. He refers to himself sardonically as “the flipping Mormon” and frets that he could become a loser like Michael Dukakis, who “can’t get a job mowing lawns.” He daringly steam irons the French cuffs on a formal shirt while it’s on his body, just before he goes down in tails to the Al Smith dinner at the Waldorf. He stays calm when he learns Obama is winning re-election: “Wow, that’s too bad,” he tells an aide on the phone. “All those states, huh?”

Drawn no doubt by word of the miraculous cinematic oil can for the Tin Man, Mitt came to see “Mitt” for the first time last Friday night. Maybe Romney sees the film less as a eulogy than a prologue. There are rumors in Republican circles that he’s thinking about another run.

A Republican fund-raising operative even told BuzzFeed that donors are so worried about 2016 now, many tell him, “I think we need Mitt back.”

It seems preposterous that we’d go through a third Romney run, but with Chris Christie imploding and Barbara Bush denouncing dynasties and shooing Jeb out of the race, maybe the 66-year-old sees an opening. Maybe he no longer feels, as he tells his family in the film on election night in 2012, stoically writing his concession speech, “My time on the stage is over, guys.”

The movie spans from Christmastime 2006, with the family gathered to make a decision on whether Mitt should run in 2008, to after the 2012 election, when he says goodbye to his Secret Service detail and returns to his empty suburban Boston home, sadly staring out the window.

I dread to think what was going through Romney’s mind as he watched a movie that made him more appealing than any of his campaign ads or his own convention, even though he paid Stuart Stevens and his other 2012 advisers ridiculously more than the winning politicos who delivered a second term for Barack Obama were paid.

But Whiteley, a charming 44-year-old Mormon documentarian who brought along his adorable blond kids — 12-year-old son, Henry, and 10-year-old daughter, Scout — to his press interviews, was trying to reveal Mitt, while Romney’s handlers were trying to obscure Mitt.

“Stuart Stevens’s feeling was that Mitt Romney was a fish out of water,” Alex Castellanos, a 2008 Romney adviser who crossed swords with Stevens in that campaign, told me. “He was a Northerner in a Southern party. He was a centrist in a conservative party. He was an elite in a rural party. Stuart didn’t think he could sell Mitt Romney in the primaries.

“Stuart thought that every day spent talking about Mitt Romney was a losing day and every day spent talking about Barack Obama was a winning day. It was criminal.”

Romney was able to relax around his fellow Mormon, Whiteley, enough to seem less awkward and strange, but he’s still in the bubble of his faith and family, seemingly cloistered from the world of average Americans.

The film glosses over one of the turning points in the campaign, the 47 percent fiasco. “I was insecure about that,” Whiteley admitted to me, noting that Romney didn’t give him a more lucid explanation than he gave the press.

It also glides over the bad symbolism of building a four-car garage elevator at his La Jolla house, which Stevens told Romney would be fine.

And while Romney offers a portrait of a man reluctantly drawn into politics because he thinks it is his duty to save the nation from people like Obama, who “have not been in a setting where you’re trying to make it,” he never really explains how he would save it or gives any clue to the Vision Thing, except murmuring about high taxes on small businesses.

In the end, despite all the campaign artifice and the brutal process, we do get to know the candidates in some primal way.

The fact that Romney allowed his strategists to keep a fence around him and his faith, which is so central to his life, the fact that he basically had nothing to say about where he wanted to lead the country, the fact that the private equity leecher spoke so dismissively about the 47 percent of people he regarded as moochers, the fact that this supposedly top-notch businessman did not seem to realize his campaign was using 20th-century technology — all of this spoke to a certain tentativeness, obtuseness and callousness.

But there’s always 2016.