Four years ago, Davis Guggenheim made one of the most spectacularly successful documentaries of all time, An Inconvenient Truth: critically beloved, a box-office smash as such things go, the winner of a great many awards, and it was the first paving stone in the road to Al Gore's Nobel Peace Price. A hard act to follow, and in the interim, Guggenheim has more or less wandered from place to place as an apparent director-for-hire: a few TV episodes, a mawkish sports drama, a music doc. But the beating heart of a crusading activist filmmaker cannot be stopped that easily, and he's finally come back with what is unmistakably a deeply personal film, that like An Inconvenient Truth all but gets down on its knees to beg and plead with you, personally, right there in your chair, to join in the fight to change the world for the better. This time, Guggenheim's target is the United States' hideously dysfunctional educational system; the movie, which premiered at Sundance to outsized acclaim, is Waiting for "Superman". And it is intellectually dishonest to an alarming degree.

Guggenheim begins with his full disclosure: after years of believing, for proper ideological reasons, that public school was an essential good for the creation of a function democracy, he found himself in the late '00s with a child just about to enter school, and, well, the public schools in the neighborhood weren't quite what he wanted, so off to private school it was! And as he drove his child (gender undisclosed) to and from that private school, Guggenheim passed by multiple run-down public institutions, and it got him to thinking about the fate of a nation in which even public schools' most passionate boosters still can't bring themselves to put their money where their mouth is.

Thus: Waiting for "Superman", its title coming from interview subject Geoffrey Canada, an immensely charismatic education specialist, who recalls the story of the day he learned that Superman, the comics hero, didn't exist. This left him heartbroken, for as he looked at the worn-out schools and homes of his neighborhood, he - a six-year-old! - could not fathom any real-world solution; if he and his family and everything he knew would ever be saved, it would take a mythic demigod.

His is the first tale of childhood woe of many: the film is chiefly structured as the story of five children, spread across America, and the problems they face as a result of America's malfunctioning education system. In D.C., fifth-grader Anthony is as good a student as he can manage; his doting grandmother knows that he'll never make it out of their failing neighborhood without better education. Bianca, in Harlem, is going to kindergarten at a Catholic school that her mother can barely afford - but as long as there is any remote way to keep her daughter on track for college and a proper job, she'll make it happen. Francisco, a first-grader in the Bronx, needs special help with reading, and his mother has tried time and again to get him into a charter school, because he's not going to get the help where he is. Emily is graduating to a fairly nice Silicon Valley high school, but she's worried that their tracking system will lock her out of the best universities. Daisy is a bright East Los Angeles fifth-grader who already knows she wants to go to medical school, but 60% of students in her district don't even complete high school. Guggenheim tracks each of these kids and their families as they apply for a lottery to get into a charter school - and there let us pause.

Go and re-read that description of the five subjects, because one of these things is not like the others. Now, I'm certain that Emily's hopes and dreams for the future are as legitimate as anybody's, and surely it would be a crime if she were denied those dreams. And Guggenheim's rhetorical point is obvious enough: substandard education isn't just an inner-city problem, it could even affect YOU, guilty liberals who make up the film's obvious target audience! Which is all well and good, except here's the rub: Emily is not just unlike Anthony, Bianca, Francisco, and Daisy, in that she's not really facing an existential threat as such, she's unlike them because she is white. And this is one of the giant gaping chasms in Waiting for "Superman", a basic social point that Guggenheim does all he possibly can to ignore: shitty education disproportionately affects minorities. That is a truth staring the filmmaker right in the face, and yet: he hedges. He simply cannot bring himself to say the "R" word: race, race, race! We are a racist country! It hurts our children!

But Guggenheim, who directed the biographical film of Barack Obama's life shown at the 2008 Democratic National Convention, appears to of that terribly sensible, left-leaning-centrist brand of "liberal" who listens to NPR, drinks fair-trade coffee, recycles, wants gay rights but not too fast or you'll upset people, thinks it's a shame about that public option but at least we have health care reform, boycotts Wal-Mart and never looks for the "made in China" sticker, and above all, assumes that we positively must be a post-racist country, because we have a black president. Of course we're a racist country: Waiting for "Superman" itself reflects this. But Guggenheim is terrified to say as much, and it's the grandest example of his film's intellectual shabbiness.

But not the only one, and arguably not the worst. The argument presented in the movie goes like this: "Our schools are failing, and we all know it. This is because our teachers suck. Our teachers suck because the teachers' unions make it impossible to fire bad teachers. Thank God for charter schools, which are more effective than public schools, though at at 20% success rate, not really successful successful. Also, it helps if we ignore a lot of the things that charter schools do to maintain their effectiveness which makes them entirely useless as a model for nationwide school reform. Hey, look at me take these five children that I have spent the whole movie humanising, and turn them into the pawns in a thriller-style climax about admission lotteries!"

That our schools are failing because we have bad teachers is not a difficult position to defend (though a useful definition of a "bad" versus a "good" teacher is not something the film pursues with particular vigor). I'm not even going to challenge him on the teachers' union thing: it's absolutely possible that he's in the right. But the "fire the teachers!" campaign that Guggenheim seems anxious to start up (exhorting us to sign up via text or the internet a good eight times during the end credits) is probably not, by itself, a good solution, and it's the only one he offers. Which wouldn't be terrible if the film was just a consciousness-raising exercise, but it is predicated on the idea that we know the school system in the United States doesn't work. We don't need to have our consciousness raised. Like An Inconvenient Truth before it, Waiting for "Superman" is a call to action: but where the global warming film had the weight of canny politician Al Gore behind it, this one is just an advertisement for the Good Intentions Express, bound for... I don't know where. And neither does Davis Guggenheim.

This much can be said: the film is slick and polished and pretty, very much unlike An Inconvenient Truth, which was basically a costly home video of a PowerPoint slide, anchored by the distinctly unlovely Gore. There's a lot of shiny, funny animation (and glib - intensely, bothersomely glib), and haunting montages, and a great deal of moving location footage. At a minimum, the director presents an exceptionally handsome case for his argument; he just doesn't provide the argument.

That's what keeps irritating me, as I think back upon the film: not that Guggenheim presents an argument I like badly, not that he presents an argument that I disagree with: rather, that he doesn't present an argument at all, while grossly oversimplifying the state of American education & culture, and he then has the gall to be smug about it. "Most public schools suck, and some charter schools are good"; that is the point where a conversation begins. It is not the point at which you start telling people to join in your crusade. You don't have a crusade, just a vast and monolithic certitude that Somebody Should Do Something About the Problems.