Ang Lee’s Brokeback Mountain first met the world at last fall’s Venice and Toronto film festivals, and though it won the top prize at the former event and was widely cited for Heath Ledger’s outstanding lead performance, there was little sense in the initial press reports that a critical and commercial blockbuster had just been born. In fact, that sense emerged only in mid-December when, within a matter of days, the film won best-picture honors from the New York and L.A. film critics associations, and opened to crowds whose sizes and excitement clearly outraced the sponsoring studio’s conventionally gradual release strategy.

How does a movie suddenly combust like this? For critics, it evidently has a lot to do with perspective and context. In September, when Venice and Toronto take place, there’s always the hope–not an unreasonable one–that the year’s last quarter will bring a healthy handful of great films to vie for the year-end honors. In 2005, that cadre of masterpieces was MIA, and among the critics I spoke with, there was a feeling that Brokeback Mountain represented a safe, agreeable consensus; if not a great film, it was a very good one that few reviewers actively disliked.

No doubt moviegoers also need an awards-season banner to rally around, and enjoy the stampedes sometimes sparked by pop culture’s herd mentality. But I must confess that I almost never anticipate such word-of-mouth frenzies, and thus am both pleased and startled when the public moves–like a single, giant organism–to embrace a movie that’s not a heavily marketed F/X extravaganza based on a beloved fantasy novel or Marvel comic-book hero.

Certainly, Lee’s film has enjoyed both curiosity and novelty value in being known as the “gay cowboy movie.” Never mind that its protagonists are actually bisexual sheep herders. The vernacular tagline proved so effective that you can still practically hear Universal Pictures’ advertising department breathing a collective sigh of relief at not having to sell America on “that bi shepherds flick.”

In fact, the phrase “gay cowboy” captures how the movie’s appeal cuts in two directions at once, cross-wiring contemporary real-world topicality and archetypal movie myth. Regarding the former, “gay,” perhaps more than any other word in the language, signifies the argument over cultural values that America has been having with itself in recent years. In the election of 2004, right-wingers were able to use the term (especially when conjoined with “marriage”) to help convert fear and prejudice into electoral majorities. Now comes the corresponding liberal push-back: Like many TV shows and movies, Brokeback opposes the abstraction of sneering political slogans with the human concreteness of individual lives, believing–accurately, I think–that when confronted with real people rather than rhetorical bogeymen, most Americans are far more tolerant and understanding than bigoted.

“Cowboy,” meanwhile, lets us know that we’re also operating in the realm of the cinematic imagination, where other forces contend. From some angles, it’s tempting to credit the film’s success simply to the fact that it finds a serviceable way to reinvigorate two genres that once were at the heart of Hollywood’s popular allure: the western and the love story. Naturally, the second of those is the more durable, and the more important in this case. As its poster art slyly suggests, Brokeback is, more than anything else, this year’s Titanic–only with a slightly provocative gender twist and a romantic backdrop composed of mountain meadows and virgin forests rather than skidding deckchairs and Atlantic swells.

Issues of sexuality aside, the film’s story (adapted by Larry McMurtry and Diane Ossana from Annie Proulx’s New Yorker short story) is a tale of first love/lost love, and, as such, it’s at its most focused and compelling in its early and final sections. Jack Twist (Jake Gyllenhaal) and Ennis Del Mar (Heath Ledger) meet in Wyoming in 1963, when both are around 19. Hired to tend sheep on gorgeous, remote Brokeback Mountain, they begin a long spell of enforced isolation amid the insinuating splendors of nature. In keeping with one of the truisms of attraction, they are effective opposites, Jack upbeat and outgoing, Ennis almost painfully taciturn.

Their sexual conjunction occurs in their tent one night without much in the way of emotional build-up. Jack throws his arm around Ennis, who reacts with a wild animalistic fury that–in a way that seems to surprise him–almost instantly turns into furious carnal engagement. (This is the only real sex scene between the men, and it’s brief.)

Later, they are left to figure out what it all means. “I’m not queer,” grumbles one. “Me neither,” comes the reply. Yet they enjoy each other’s favors throughout the summer. When they descend from the mountain, both seem willing to leave their alpine passion behind. It’s four years before they meet again and resume where they left off.

Do we believe this grand amour? One critic called Brokeback‘s central relationship “bizarrely passionless,” and I understand why. Though we’re given to understand that the two men connect sexually, that’s more stated than demonstrated; they generate little erotic heat. Likewise, though exhibiting complementary personalities, they don’t display the kind of catalytic emotional chemistry that suggests a decades-long romance. I’m afraid I attribute these deficiencies mostly to a kind of lazy, half-baked quality in the film’s script, but for most viewers they’re obviously not fatal flaws, and there are two reasons for that, I think.

First, people believe in Hollywood love stories chiefly because they want to believe; the filmmakers don’t need to supply dramatic logic and precision so much as they do a kind of attractive sentimental scrim onto which viewers can project their own wishes and fantasies. Second, the key ingredient in most Hollywood movies with genuine dramatic ambition is at least one commanding star turn, and Brokeback has that in spades.

Indeed, Heath Ledger’s performance is the film’s one aspect of unqualified artistic triumph. In the tradition of Brando, Clift and Dean, the actor seems to invent a whole language of clench-jawed mumbles, scattered glances and bodily constriction to suggest a man of raging inner contradictions. A kind of character acting writ large, this is one of the two classic modes of American screen performance, and perennially the more impressive. The other mode, which involves the actor seeming to be himself rather than disappearing inside the character, is nicely exemplified by Gyllenhaal’s Jack, a smart if inevitably less startling performance.

One of America’s most gifted directors of actors, Ang Lee deserves a large measure of credit for these turns as well as for the fine work of Michelle Williams as Ennis’ wife Alma and Anne Hathaway as Jack’s wife Lureen. Lee has often said that his main theme as an artist is repression, the conflict between social norms and inner impulses, and Brokeback certainly offers him plenty of congenial material. Aside from the acting, however, the quality of his contributions is notably uneven.

Though consciously evoking models like John Ford and Anthony Mann, Lee’s visual approach to his mythic western settings lacks their inspired rigor, settling too often for the mundanely realistic or the merely pretty. When the story resumes its account of Ennis and Jack’s relationship, wending through years when the characters escape their families and exercise their passion only during periodic fishing trips, the narrative itself grows flabby and anecdotal. Though it recovers in its very moving final scene, the whole has much that’s expendable or unaccountably clunky.

Here’s a particularly egregious–and, I think, revealing–example. As noted, for years Ennis and Jack go off on weeklong trips to the mountains where they (presumably) make love and (supposedly) fish. But then comes the big blow-up where Ennis’ suspicious wife finally confronts him, saying “All this time you’d leave and take that fishing tackle box, but not once did you open it. I know because I put a note inside asking you to bring me and the kids some fish, and you never even saw it.”

So we’re to believe that Ennis and Jack went to the Wyoming wilds year after year and never touched a fishing pole? Sorry, but that strikes me as the stupidest thing I’ve seen in a serious movie in a very long time. It’s stupid because it totally ignores who these characters are. Notice: They’re not Gold’s Gym queens who never set foot outside of North Raleigh. They’re rugged western outdoorsmen who’ve spent their lives in the wilderness; they love to ride, hunt and fish. These guys don’t go off to the mountains just to screw. Patently, they screw and they fish–you might even say that’s their idea of heaven.

Though this scene can be regarded as simply a baldly obtuse piece of melodramatic writing, I’m afraid its ignorance of character infects even the film’s implicit political dimension. In effect, Brokeback is a romance that captures the special spell of one’s first love, the kind that flourishes only in the blush of youth. Countless other dramas, from Elia Kazan’s Splendor in the Grass to the McMurtry-penned Last Picture Show to the trailblazing BBC series Brideshead Revisited (a work centered on gay/bisexual men), survey similar emotional Brigadoons and acknowledge that all are ultimately vulnerable to the tragic onslaughts of time and age.

Lee’s film, on the other hand, wants to hold on to the fantasy that everything that “Brokeback Mountain” represents to Ennis and Jack might somehow have been preserved forever. To do this, it must downplay all evidence of their divergent characters (Jack evidently sleeps with many men including male prostitutes, while Ennis’ other romantic interests are female) in order to hint that the two men could have stayed together as a couple were it not for the terrible force of “homophobia,” two instances of which are clumsily inserted into the story at crucial points.

While it may further burnish the film’s romantic sheen, this kind of politically thwarted, would-be “happily ever after” is just as phony and fantastical as the old, achieved kind. It tells us that life is all a matter of social structures and political arrangements rather than the messy exigencies of character, fate and individual choice. That tendency is what finally drags Lee’s film away from art into the realm of P.C. sermonizing.