“Michael Moore in TrumpLand” arrives as a sneak attack. The movie was shot 11 days ago, and it was only over the weekend that Moore arranged to have it premiere on Oct. 18 at New York’s IFC Center. (It opens today for a week in New York and Los Angeles, and will be available on iTunes.) The fact that Moore kept the film’s existence under wraps and launched it seemingly out of the blue speaks to his showbiz instincts; it’s his October surprise. Going into the premiere, I don’t think I was alone in wanting the movie to be a cathartic IED thrown into the already gliding-off-the-rails surrealism of the election season. Unfortunately, “Michael Moore In TrumpLand” turns out to be a tossed hand grenade that doesn’t fully detonate.

The movie is 73 minutes long, and it’s simply the filmed version of Moore’s recent one-man stage show, which he’s been presenting in Ohio. The show was designed to be performed in the heart of Republican country, and that makes sense. Moore has always been accused of preaching to the liberal-left choir, but in this case he decided — wisely — to preach to the anti-choir. The movie was shot at the Murphy Theatre in the southern Ohio town of Wilmington, a region so conservative that the theater’s benefactor is Glenn Beck. Up on the marquee the night of the show, the words “Trump Voters Welcome” are placed in red lettering, and there are a lot of Trump supporters in the audience — and also Hillary supporters, Bernie supporters, third party supporters, and undecideds. It’s not a hostile crowd; it’s just not the usual wall-to-wall Michael Moore progressive one.

For a while, Moore, with his stringy long hair tucked under a San Francisco 49ers cap, stands at a podium and speaks in the style of a free-wheelingly funny and scathing professor. (That’s the best part of the movie.) Then he gets more earnest. In “Michael Moore in TrumpLand,” he’s at once a stand-up comedian, a hectoring editorialist, a can’t-we-all-get-along negotiator, and a warm-and-fuzzy Hillary Clinton advocate; he’s also a filmmaker rehashing a number of the inspiring points he has already made in films like “Sicko” and “Where to Invade Next.” And Donald Trump? He, of course, is the reason that anyone is going to be excited to see this movie. But Moore’s title turns out to be a bit of false advertising. The filmmaker means it quite literally: He’s giving a stage performance in the heart of Trump-land. OK, fine. But the real lure of that title is that it promises the fullness of Moore’s take on Trump: a deep dive, a perception to spin our noggins around or make us laugh, in the way that Michael Moore can, with a cathartic slap of recognition at something that — gulp! — we haven’t heard before.

He starts off by doing that. Moore, backed by looming photographs of the beautiful young Hillary Clinton, offers an analysis of Trump that’s all about the decline and fall of the white male in America, and he does a terrific riff on the agony that a lot of men feel. White men over 35, he announces, are just 19% of the population. They’re fading! And they’ve been reduced to glorified tools who have the ability to distinguish themselves in one of two ways: they can procreate, and they can reach for things on the top shelf. (Two tasks rendered borderline irrelevant by in vitro fertilization and lightweight step ladders.) The riff works because it’s rooted in Moore’s sympathy — the fact that he himself is part of that once dominant but now diminishing breed, and he knows it. Yes, he talks about the loss of jobs and security and family, but mostly he talks about the loss of ego. He’s brilliant in discussing the 2016 Super Bowl halftime show, with Beyoncé leading her army of black-clad feminine “s—kickers” as a key signifier in the takeover of cultural power by women.

To Moore, an angry white guy like Donald Trump provides a feeling of deliverance, as well as a promise: We will take it back to how it was. Moore is honest enough to see his own sensibilities reflected in the cosmic gripe of Trump supporters. They’re in a rage at a lot of the same things he is: a government, and a corporate economy, that are no longer organized to take care of people. But the choice that Trump voters make is to lash out, and to back someone who pledges to destroy the status quo. As Moore testifies, Trump is likely to destroy it, all right — along with everything else. Moore is at his best mimicking the sound of male Trump supporters at rallies (a wail of fury fused with a caterwauling of pain) and calling it the sound of a dying dinosaur. Solidly, he builds the ground floor of an argument. I was eager to hear what he’d say about Trump next.

Well, that’s all he has to say. As soon as Moore is done discussing the angry white male, he’s finished talking about Trump as well. After half an hour (at most), he veers over to the subject of Hillary Clinton, and why Republicans hate her with such religious passion. Now, Hillary is not exactly an unworthy, or irrelevant, topic in this electoral season. Yet the intensity, the insanity, the singularity of the election — and, let’s be honest, the whole come-on of Moore’s movie — is rooted in the mystique of Donald Trump. And Trump deserves the full force of Michael Moore’s analysis. Moore, in my opinion, wrote the single most penetrating piece that’s been written about this election — his over-the-summer missive entitled “5 Reasons Why Trump Will Win.” That title may sound out-of-date, in light of the sexual revelations that will likely be the key torpedo of Trump’s candidacy, yet really: Can we so blithely dismiss his popularity before that fatal videotape? Can we be so sure he wouldn’t have won? Unlike much of the mainstream media, Moore can’t be accused of reveling in a cavalier dismissal of the Trump phenomenon. He has pointedly critiqued that dismissal.

So why, in “Michael Moore in TrumpLand,” does Moore’s analysis begin and end with the angry-white-male argument? He’s correct in saying that Trump voters “want to use the ballot as an anger-management tool,” yet that doesn’t do justice to the range — and the media hall-of-mirrors quality — of Trump’s astonishing loyalty of support. What about the endlessly resonant fact that Trump isn’t a politician, but that he played one — or, at least, a boardroom demigod — on TV? Take away Trump’s reality-TV celebrity, and you don’t have a candidate. (Moore never mentions it.) Beyond that, the feeling shared by so many Trump supporters that their blustery boardroom Elvis is just what’s needed to clear away the wreckage of a broken system puts them, in many ways, in the same camp as Bernie Sanders’ supporters. Moore, in this movie, doesn’t do justice to the powerful allure of that view. But that’s because, after his own bashing of the system, he now turns around to massage his own propaganda. “Michael Moore in TrumpLand” turns out to be a political love letter to Hillary Clinton from someone who wouldn’t have written that same letter eight months ago.

The film starts off as a winningly acerbic piece of political theater, but it turns into the story of a religious conversion. Moore wants to do everything he can to steer the sympathies of the audience toward Hillary. He musters a convincing and highly moral defense of Clinton, talking about how unfairly she was humiliated by the press during the ’90s. He pays justified homage to the compassion she poured into her commitment to health care, and he’s cheeky in confronting conspiracy legends — the kind that fuel Trump voters — like the notion that Vince Foster was murdered. Did Hillary kill Vince Foster? “I hope she did!” says Moore. “Because that’s badass.”

Moore wants to convert the Trumpian masses, but really, the religious conversion he’s documenting is his own. Hillary the compromising centrist, he seems to be saying, “will turn out to be everything I believe in!” That’s called magical thinking. He suspects, deep down, that Hillary will be like Pope Francis: a revolutionary snuck in through the Trojan Horse of mainstream politics. And right there on stage, in front of an audience of people who don’t like Hillary Clinton (but start to tear up — or, at least, the women do — when he talks about her), he gives in to his dream. What if the young, idealistic Hillary — the liberal Hillary — had simply gone underground? “I think she’s been biding her time,” says Moore.

He now has the hope that if elected, she’ll do the things that he has long wanted a president to do. She’ll sign executive orders releasing non-violent drug offenders from prison! And outlawing the use of high-fructose corn syrup! And, predicts Moore, she’ll finally end the gridlock! If you think you’re getting déjà vu all over again, you are: It’s called a flashback to the heady days of Barack Obama’s 2008 campaign. But at that point, there was a certain romantic justification for the optimism: Obama was an unknown quantity, and his rhetoric soared. In “Michael Moore in TrumpLand,” Moore turns Hillary Clinton into a paragon of tough liberal sainthood, but that comes off as nothing so much as a projection of himself. It’s one more echo of white male privilege.