“Citizen Penn” is a documentary about Sean Penn‘s path from Oscar-winner, tabloid target and sometimes hectoring political activist to a humanitarian aid worker of the first order, a Hollywood star who has turned his celebrity into a magnet for drawing media attention to human and environmental disasters.

It’s one of those movies that folks who’ve made up their mind about Penn based on comedian mockery and Fox News “enemy of the state/useful idiot” labeling will never bother to watch.

Still, as it premieres on Discovery+ (May 6), maybe some enraged hater or three will stumble across it and maybe soften their views on his very serious, very public charity work, something most of the media and much of the country has already done.

“Citizen Penn” is built upon archival news coverage — an opening montage summarizes his Oscar win, his assorted tabloid moments with Madonna and others — on footage gathered by a trusted friend and fellow aid worker in Haiti, and a long sit-down interview. with the filmmaker.

Penn uses the film the way he promotes his major charity, which started life as J/P HRO (Jenkins/Penn Haiti Relief Organization). He accepts the spotlight, then takes it and points it at the work and the many others in league with him carrying it out — doctors, volunteers, Haitian officials and members of the U.S. military. He names names and filmmaker Don Hardy (Penn narrated Hardy’s 2008 doc “Witch Hunt”) shows the faces of those Penn celebrates and honors as heroes of the struggle to provide help in Haiti after the 2010 earthquake that flattened the country, and the hurricane that threatened to flatten it again.

“The best humanitarian aid organization ever built is the United States military,” Penn declares, showing how his team, thrown together in the days after that January of 2010 cataclysm, eventually embedded with the Army. When the Army was withdrawn, J/P HRO took over feeding, doctoring, organizing and relocating some 60,000 Haitians who moved onto an abandoned golf course in the days after the quake.

The film is dominated by on-the-scene/ground-eye-view footage of the disaster, with J/P HRO using Penn’s name and face and connections to get help, on the spot, to those who needed it.

We see an actor widely-condemned for buddying up to Venezuelan leader Hugo Chavez recall putting in a call to Chavez for the first thing he heard Haiti was in desperate need of — morphine for pain relief in the overwhelmed, triage-centered hospitals.

“An actor in Hollywood knows how to find drugs,” he jokes. But 350,000 vials of painkillers?

They fly into Haiti with thousands of Chinese water-purifiers, which they distribute to churches and train aid workers to operate in the early days of the disaster.

And they interrupt a U.S. Army Lt. Colonel’s morning shave to scope out their chopper friendly, logistics-mastered base of operations, and throw in their lot with him and his men. When the Army — some 22,000 U.S. troops were sent to help by then-President Obama — withdrew, that Lt. Col. and Penn “persuaded” the Army to leave the fully-equipped hospital tent they were running for Penn’s charity to operate.

Weeks and months went by and the media coverage moved on. But here was Anderson Cooper, “stunned” to see Penn & Co still there, still at it months later.

Those months — which moved from triage to civil engineering, getting a rubble-filled street in an abandoned district cleared — turned into years and then into something permanent, building a Haitian civilian conversation corps to plant trees and start dealing with the island’s deforestation and environmental degradation, which make every disaster there worse.

The film’s more personal touches range from a day and night sprint through Port au Prince, looking for diphtheria serum to save one newly-diagnosed child from disease, a broken social safety net and indifference — a vast stockpile of medicines and aid that no one had organized to distribute — to Penn’s amusingly blunt fund-raising appeals in an annual Hollywood charity gala.

“I get worse and worse at it,” he confesses with a laugh, owning up to his rep as a guy whose intensity about his causes rivals the intensity he shows on screen. He’s always breaking the cardinal rule of humanitarian charity fund-raising, something public speaking clips here amply demonstrate.

“Don’t bum out the crowd” if you want them to donate.

The most revealing material in “Citizen Penn” might be his own doubts about the limits of what one charity can do in the face of a catastrophe of this scale. He notes that keeping his eyes on the ground and faces in front of them, solving one problem, getting help to another day’s traumatized victims, let him believe “the ‘big picture’ is fixable.”

And then he gets into a helicopter and sees the destruction spread far and wide and realizes that he has no idea what they’re all up against.

“Citizen Penn” isn’t a wholly balanced portrait of the “do gooder” star and humanitarian. It flirts with turning towards hagiography, here and there.

But what it manages to get across is that dismissing Penn and his passion for philanthropy of this sort is a mistake, that he’s sincere, committed to the long game., and an impatient man-of-action pretty good at articulating why you should pitch in, too, in whatever way works.

MPA Rating: unrated, profanity

Cast: Sean Penn, Cécile Accilien, Anderson Cooper, Ann Lee, many others

Credits: Scripted and directed by Don Hardy. A Discovery+ (May 6) release.

Running time: 1:32