“Nashville,” by any reckoning one of the landmark achievements of the American film industry, has been described as Robert Altman’s “birthday card” to America on the 200th anniversary of the American Revolution. As celebratory gifts go, “Nashville” was an exploding cigar, if there ever was one. Viewing the film 30 years later, on the unhappy occasion of the death of its creator, a younger audience might need to be reminded that it was made during the Watergate scandal and the fall of Saigon, when the assassinations of Martin Luther King and the Kennedy brothers were still fresh wounds. America was not feeling good about itself, Americans were not feeling good about each other, and acerbic, politically astute artists like Robert Altman were in a very bad mood indeed.

In 1975, I was a newspaper film critic. Gerald Ford was midway through his brief unpremeditated presidency, and soon to be evicted by disgruntled voters who were ashamed of electing Richard Nixon twice and damned if they were going to endorse the man who pardoned him. It’s ironic that Ford and Altman should have died within a few days of each other, one praised fulsomely for bringing a measure of “normalcy” back to America (essentially, for not being Richard Nixon), the other praised tentatively for “Nashville” and a dozen other films that make a compelling case for America’s incurable abnormality. It’s no coincidence that Altman’s career flagged in the Feelgood 1980s, while Ronald Reagan’s dim impervious sunniness helped the stupid and the affluent to pretend, in smug defiance of inconvenient facts, that everything American was turning up roses and buttercups.

The same smiling people who found “Nashville” anti-American in 1975 will find it so today–we never run short of see-no-evil Chamber of Commerce types, who were among Altman’s favorite targets. (They dress like Ned Beatty in “Nashville.”) The Chamber of Commerce is a wretched model for patriotism, as every moralizing liberal reminds us; the true patriot is the one who cares enough to criticize. But it was Altman who showed us how to turn “tough love” for your country into art. His final film, “A Prairie Home Companion,” which returns “Nashville”‘s Lily Tomlin to center stage, is a dark-edged but nostalgic, even sentimental American portrait that shows us where Altman’s heart is–in a place not so far distant from the heart of “Prairie” progenitor Garrison Keillor, who’s often dismissed as a cornball by people who don’t quite get him.

In 2006, George Bush and geopolitics have made anti-Americanism almost mandatory for foreigners. But it’s not so easy for us natives. Robert Altman was from Kansas City. His classic “McCabe and Mrs. Miller,” the Euripidean tragedy of an entry-level frontier entrepreneur, is made from the same stuff–love and anguish–that Arthur Miller put into “Death of a Salesman.” It’s as somber as “Nashville” is exuberant, the flip side of a tortured patriot whose love for his homeland was unrequited. And don’t forget that the most appalling character in “Nashville,” among all those screwballs and frauds and predators, is a Brit. The BBC correspondent played by Geraldine Chaplin is such a savage caricature that it’s hard to believe Altman wasn’t working from a live model.

The more convincing charge is that the film is anti-Nashville, or at least guilty of stereotyping an arcane micro-culture that Altman never really tried to decipher. It might be true as far as it goes: A great insider’s portrait of Nashville has yet to be filmed. But Altman knew exactly what he needed, and what he had in spades was what you might call the acupuncturist’s instinct. He wanted to slip a long therapeutic needle into one of America’s soft places, to instant and unmistakable effect, and Nashville was his brilliant choice.

Las Vegas was too raw and cheesy, and for the Hollywood-scarred Altman LA was too easy (he settled scores with it years later in “The Player” and “Short Cuts”). Nashville, like other cities that brew their adrenaline from entertainment, offered him what I once called a “slippery” surface. Here people are performing, emoting, voguing, vying, faking, acting out, selling out. There’s more sincerity in most of the songs than in most of the singers. The country talent wears a lot of white hats and black hats, but it isn’t like the old Westerns where the white hats are the ones you can trust. Altman never learned Nashville’s secret passwords, and he never expected the locals to admire his work. But his nose, seasoned in Hollywood, led him unerringly to the fraud, fear and insecurity behind the rhinestone glitter–the schizoid freakiness that makes accurate psycho-portraits of America feel like journeys through the Land of Oz.

Even critics unconvinced or unimpressed by Altman’s vision of a society coming unglued (while the choir sings “You may say that I ain’t free, but it don’t worry me”) are obliged to look back and concede that “Nashville” was rife with prophecy. America’s obsession with celebrities, its fatal substitution of commercialized voyeurism for civic engagement, was already getting eerie when Nathanael West catheterized the dark heart of Hollywood in “The Day of the Locust,” in 1939. When Altman was filming “Nashville,” with its wild operatic finale that must owe something to West’s novel, People magazine was in its infancy, Rupert Murdoch was still an Australian and TV’s face factory was cranking out celebrities with slow primitive technology. Celebrity hysteria, the identity-erasing mental illness it represents and the trash media that exploit it have all multiplied a millionfold in the 30 years since Altman scandalized Music City. Vicariousness is the bird flu of the 21st century, with no vaccine in sight.

“When you open a celebrity magazine, it’s all about the money and being rich and famous,” Cameron Johnson, 22, tells an interviewer from the Pew Research Center. “We see reality TV shows with Nick and Jessica living the life. We see Britney and Paris. The people we relate to outside our friends are these people.” Pew’s recent telephone survey of Americans 18-25 revealed that getting rich (81 percent) and famous (51 percent) is what matters most to our next generation of adults. According to one Robert Thompson, who teaches popular culture at Syracuse, “The culture is obsessed, absolutely ravenous, about all things celebrity right now.”

Altman warned us, but in 1975 no one could have imagined the depths of the pathology that lay ahead. The most painful, lump-in-the-throat-inducing scene in “Nashville” comes when the waitress Sueleen (Gwen Welles), perhaps the worst singer in the state of Tennessee, is coerced into stripping at a political smoker where the randy old boys can’t believe she was hired just to sing. Sueleen’s humiliation brings old-timers like me to the verge of sharing her tears. It wouldn’t have the same effect on contemporary 18-to-25s, who embrace ritual humiliation of the aspiring but untalented as staple entertainment. “American Idol” and its host of “reality” imitators grind up pitiful dreamers like Sueleen on a daily basis, to earn some of the highest ratings on television. And unlike Sueleen, the losers are real live victims, backstage crying real tears. Somehow we’ve bred a generation of stonehearts who would have been comfortable in Nero’s skybox at the Roman Colosseum, cheering for the lions.

It may seem archaic now, but Altman’s sympathy for the underdog, for the trapped and the marginal and the unaware, was paradoxically seductive to what Hollywood considered the “youth” market in the ’70s. The success of “MASH” established Altman, already 45, as a “hip” filmmaker who could deliver the psychedelic audience along with disillusioned veterans and opponents of the war in Vietnam. Between 1970 and 1975, with “McCabe,” “California Split,” “The Long Goodbye,” “Thieves Like Us” and ultimately “Nashville,” Altman redefined the “Hollywood” movie and became a reluctant guru for an alienated generation that was not his own. What he offered us was more corrosive than satire, more cathartic. Vintage Altman was a harsh laugh with a cringe attached.

The young, apparently, were so much older then. Altman’s films demand patience, undivided attention, irony, political and aesthetic sophistication and a fairly mature awareness of the tragicomic human condition. He deliberately sought “R” ratings to keep children and adolescents out of his audience, because he felt they lacked the patience his films required.

“I’m trying to present something to an audience where they have to work a little bit,” he said, defending his overlapping dialogue and chaotic soundtracks. “They have to invest something. You don’t hear everything somebody says in real life, do you? That’s the illusion I want. It’s a way to get the audience involved and participating in the thing.”

He can be a challenge. In a flawed picture like “Quintet,” the narrative may elude the most dedicated cinephile. “Short Cuts”–“Nashville” reset in LA on meaner drugs–is a tapestry with a higher thread count than many film critics could negotiate. But with Altman your hard work never goes unrewarded. After a Christmas week dedicated to screening his classics, a lone visit to my local multiplex was devastating–especially the coming attractions, which without exception featured comic book superheroes, animated animals and robotic toys brought to life by special effects. “The people who go to movie theaters now are teenagers who just want to get away from home,” Altman recently sneered. But even that seems generous. None of the previews I saw were aimed at anyone who could go to a movie without his mother.

Conclusive evidence, I’m afraid, that the rapid infantilization of American culture is complete and irreversible. Something–TV, I suppose–has been deadening sensibilities, lowering expectations and reducing attention spans with a cumulative effect that’s almost counter-evolutionary. Movies that engaged and satisfied the mainstream audience of the ’70s–Altman’s audience–are art films, even elitist niche films today. “Adult films” used to mean films for adults; now it means porno, and that’s all it means.

While the studios sifted demographics and dreamed of foolproof formulas, Altman, like Dr. Frankenstein, never seemed to know exactly what the characters he created were going to do. His career spanned the entire history of television (“Anyone who thinks TV is an art medium is crazy–it’s an advertising medium”), as well as the brief flowering and prolonged withering of American cinema. It’s mind-expanding to consider that the same hand that shaped “Nashville” and the black magic of “Vincent and Theo” also directed Zasu Pitts and Gale Storm in the Eisenhower-era sitcom “Oh! Susanna.” Long before his death, Altman understood that he was a dinosaur, an undiminished but unwelcome old outlaw on the fringe of an industry grimly committed to its own intellectual suffocation.

“I fiddle in the corner where they throw the coins,” he said. “Where I can get my work done.”

In Altman’s case, “We’ll never see his like again” is not funeral rhetoric, but plain truth. In America, the age of the auteur is over. Stanley Kubrick is dead, Woody Allen’s still working but hard to find. For A-list film directors, all the choices are bitter ones: service the kiddies, shoot action techno-schlock or sell the chateau in Bel-Air and go back to Sundance. The last director who makes money with films of his own choosing and device is Clint Eastwood, an iconic movie star with a surprising sensibility and a nice touch around the cameras. But if you designate The Truth as the bull, Eastwood is a picador and Altman was a matador, a Manolete whose sword rarely missed a clean kill.

Yet never on the first pass, of course, or the tenth. Altman made every audience earn its truths; he disparaged lazy audiences and lazy actors, too. “What I’m looking for is occurrence,” he said. “Truthful human behavior. It makes for a lot of editing but I like to go on a journey with the actors. We’ve got a kind of road map, and we’re making it up as we go along.”

Altman was the deadly enemy of conventional wisdom and safe assumptions. As a filmmaker, his approach to a genre or any time-honored tradition was to poke it with a stick, light a fire under it and see what crawled out. As a citizen he was an outspoken critic of the ascendant Right, a liberal who swore in 2000 that he would move to France if George W. Bush was elected. None of his home truths were comforting. He believed that human behavior was often scarier than we can bear to watch or acknowledge, but his compulsion was to show us anyway.

Everything he believed about the United States of America is in “Nashville.” Americans had everything, Altman would say–energy, talent, courage, intensity, perseverance–but what we never had was a clue. We were a nation of inchoate yearnings. Then the yearnings kind of dried up and the inchoate took over.

A handful of filmmakers are revered as wise men, as sages of the art: Renoir, Bergman, Fellini, Kurosawa, all of whom Altman claimed as his teachers. Many think of Robert Altman as a wise guy, too rude and caustic–too American–to place in such exalted company. But I suspect that time will be very kind to Altman and his fierce indelicate wisdom.

“Wisdom and love have nothing to do with one another,” he said once. “Wisdom is staying alive, survival. You’re wise if you don’t stick your finger in the light plug. Love–you’ll stick your finger in anything.”