The films of Michael Moore have been faltering at the box office for several years now. This weekend, though, the lackluster performance of his latest truth-to-power opus, “Fahrenheit 11/9,” was notably dramatic, if not downright stark. The movie is a sequel, of sorts, to “Fahrenheit 9/11,” Moore’s scathing riff on the administration of George W. Bush. That movie, when it was released in 2004, made $119 million, becoming the highest-grossing documentary of all time. It was a special moment, of course. America was still grappling with the shock of 9/11, and Moore’s film became a lightning rod — a catharsis for liberals (or some of them, anyway) and a symbol, for conservatives, of everything that was wrong with liberalism. But one thing, perhaps, that everyone could agree on is that in “Fahrenheit 9/11,” Michael Moore, for good or ill, had become instrumental in defining the national dialogue.

“Fahrenheit 11/9,” his scathing riff on the administration of Donald J. Trump, will be lucky to gross one-tenth of what “Fahrenheit 9/11” did. That’s more than just a staggering comedown. It symbolizes a couple of things at once: how different the two eras are, but also how Michael Moore’s audience — there’s no other way to put it — has gradually drifted away. It symbolizes that Moore is no longer defining the dialogue. A Trump-era conservative would probably say, “It’s about time! Michael Moore has lied so much that it’s all finally caught up with him.” A Trump-era liberal would probably say, “I still agree with him, but I’ve seen enough Michael Moore movies. I know his message already.”

There are elements to be heeded in both those statements (even as a Moore believer, I’ve been troubled, on occasion, by his willingness to bend the truth to make a larger point). But the question of why Moore’s films are no longer connecting with the public in a major way has a meaning beyond the standard left/right dialectics. It’s about a problem that Moore may be able to solve, but if so, he’s going to have to rethink what he does. Not the content but the execution. Because as much as I remain a fan of Moore’s (I thought the cumulative effect of “Fahrenheit 11/9” was chilling), what he’s doing now is not, in the fullest sense, working. He needs to decide if he wants to rectify that.

It’s been nearly 30 years since “Roger & Me,” and through all that time Michael Moore has remained a robust public figure, iconic in his baseball hats and pleasure-loving Middle American girth and can’t-be-bothered-to-cut-it long hair, fearlessly funny and incisive in his rhetoric, stirring up debate on TV news shows with his crackling blend of heat and light. In the summer of 2016, Moore issued a lengthy and eloquent missive to establishment liberals telling them that they had their heads in the sand about Donald Trump’s popularity, and about his potential to be president. Basically, he predicted Trump’s victory — not just the what, but the why. It’s no accident that Moore called that one so accurately; time and again, he has kept his finger on the pulse where others haven’t. He understands working-class America, and in 2018 that means he understands Trump’s America. If you’ve continued to watch his films, you may feel (as I do) that Moore has not lost his provocative vitality as a documentary artist.

Yet let’s be brutally honest, since the Michael Moore I know would insist on nothing less. When a documentary filmmaker, for most of three decades, has been defined by his ability to stir up national political debate and even drive it, and to present himself as that all too rare thing in American life, an uncompromising mainstream muckraker, it’s meaningful when his popularity and influence begin to erode. It means that even if he hasn’t changed, his relationship with the public has.

It’s important to ask why. In Moore’s case, there are a handful of reasons, only one of which is Moore’s filmmaking. That’s now part of the problem, but let’s be up front about what the more prevalent issues are:

The Internet has fractured how we get our information. When Moore made “Bowling for Columbine,” in 2002, he put forth essential arguments about the gun debate, and the historical culture of American violence, that people still reference. The movie itself felt like a loaded weapon. (A number of viewers hated his ambush of Charlton Heston, but in that moment I felt that Moore revealed the hypocrisy of gun advocates.) The film grossed $21 million, but even that solid sum barely measured how much it became part of the conversation. Today, by contrast, the conversation about guns is more or less everywhere, rippling through comment boards and news shows and cell phones and, yes, documentaries, some of which have been superb (like 2016’s incisive portrait of the NRA, “Under the Gun”) even as they’ve remained mostly off the radar. It’s much harder for one movie to break through and become a giant billboard of issues the way that “Bowling for Columbine” did.

Moore’s audience has aged out. A generation of liberal viewers grew up with Michael Moore, but it may well be that they no longer go out to the movies. At least, not in the way they once did. He’s like an aging rock star putting out albums that simply don’t mean as much to those who were, and are, his core fans. But what about the next generation? If anything, they’re even more of Moore’s ilk: ardent, progressive, dogmatic in their passion. There’s just one problem: The under-40 generation, raised by technology, has demonstrated that it feels almost no desire to act out its progressive impulses by going to the movies. That’s what their parents did. Remember “Citizenfour,” the Laura Poitras documentary about Edward Snowden? It became a mythical media touchstone. And guess what? Hardly anyone saw it.

In the Trump era, people are addicted to the news, but they’re also sick of it. They don’t want to go out to a movie and rehash the Trump presidency they’re already living on a nightly basis on MSNBC. Simple as that. I mean, seriously, who hasn’t felt the burnout? Then, of course, there’s a highly related phenomenon, known as…

The let’s-just-tune-it-all-out factor. Everyone talks about activism, but when it comes down to it many of us would rather just sit around and binge-watch “The Walking Dead.”

In 30 years, Michael Moore has made 10 feature-length documentaries, and for a while every one of them was a sensation: “Roger & Me,” “Bowling for Columbine,” “Fahrenheit 9/11.” Then, after “Fahrenheit 9/11,” his all-time zeitgeist hit, Moore directed what may be his single most vital film, one that tapped into a topic every sane person in America agrees is of transcendent importance: health care. “Sicko,” released in 2007, was a seismic and disturbing exposé, built entirely around people who have health insurance. It was about the gaping chasms in the system — about the way that even our “coverage,” chipped away at by greed, was starting to rot from within. The movie did well; it grossed $24 million. Yet it was Moore’s last moment of heightened relevance.

In 2009, Moore made “Capitalism: A Love Story,” and it was a seriously problematic movie: a riff on what had gone wrong in America in the last 50 years that wound up fingering capitalism itself as the culprit. But it’s as if Moore, in all his acumen, had forgotten the old saw about capitalism: that it’s the worst system except for all the others. The movie was a free-form harangue, hectoring yet fuzzy, all sealed with the let’s get socialist! boosterism that has become Moore’s signature parting gift. (For a guy who was so hard-headed about the ascendance of Donald Trump, he’s awfully soft-headed about the appeal of Bernie Sanders.)

Ever since then, Moore’s films haven’t been compellingly focused documentary essays, like “Bowling for Columbine” or “Sicko,” so much as free-form didactic rambles. “Fahrenheit 11/9” is a good example. I remain one of its admirers, yet even in my mostly positive review I had to acknowledge that the film was all over the place: thumbing its nose at Trump, detouring into a dead-serious exposé of the Flint poison-water scandal, then building to a revelation of how the Trump administration is threatening to trash democracy even more than many liberals think. If you stay with the movie, it all adds up, but for long stretches you have to indulge its stream-of-opinionizing form. That makes it feel like something less than a bull’s-eye. And the point of this weekend’s box-office numbers is that people can’t stay with something they aren’t even bothering to see.

Is there a solution? A way for Moore to staunch the bleeding out of his identity as a liberal-left documentary superstar whose movies were once events? I ask this as a Michael Moore fan, a Michael Moore believer. I share much (though not all) of his vision; I also think that he’s a wizardly filmmaker. But maybe what he needs to do is step back from his familiar tropes about what’s happening to America and look at something from a different angle. Here’s one idea.

On the eve of the 2016, Moore dropped a film out of nowhere called “Michael Moore in Trumpland.” I went to the suddenly announced screening having no idea what it was about, only to learn that it was a hastily shot film of a one-man show that Moore performed in Ohio, where he basically wound up begging an audience full of undecided voters to please please please cast their votes for Hillary Clinton (who he had often excoriated, but that’s another story). The film came out on iTunes and didn’t have much impact. But what piqued my interest, and stayed with me, was the title. “Michael Moore in Trumpland.” I heard that and thought: That’s just where Michael Moore should go.

What I thought the movie was going to be about was Moore heading into the heartland and speaking to Trump supporters, trying to see the world from their side. Sure, that’s been done before, but my hope was that Moore, with the bone-deep Flint values that, for all his celebrity, I believe he has never abandoned, could speak to people in our divided America with a uniquely inquiring spirit. I thought he could do it and bring the news. I still think he could. Or do something else just as out of the box. But he’s no longer going to bring the news to anyone if he isn’t willing to surprise us by surprising himself.