CANNES – A late, not-entirely-incidental scene in “Behind the Candelabra” finds Swarovski-encrusted pianist Liberace holding forth on the 1981 Academy Awards. The showbiz legend is due to make his long-desired debut appearance as performer and presenter, and you may or may not be surprised to learn that he”s backing “On Golden Pond,” that maudlin, Vaseline-lit ode to comfortable expiration, to take the gold. “I”m so glad Jane Fonda”s dropped all those awful causes and made a nice film with her father,” he coos primly. “Our job is to entertain the world and sell lots of drinks and souvenirs.” 

Steven Soderbergh”s alternately raw and riotous account of the last years of Liberace-if that sounds like a reference to an era rather than an individual, it should-is crammed with delicious asides like this, and they”re not the throwaways they initially seem. Much of the film”s blithest humor is used to expose its subject”s deepest social and personal limitations, though its stance is more bemused than vindictive: as well as a touching and tough-minded love story, “Behind the Candelabra” is a sympathetic study of a man defiantly resisting his own significance. Its own causes, still politically hot a quarter-century after the man”s death, are subtly enfolded into its goggle-eyed celebrity spectacle. It”s entertainment with a capital, fur-lined E, though I suspect Liberace wouldn”t have cared much for it.

For one thing, the musician who yearned for big-screen stardom probably wouldn”t have been amused that his outsized life is being treated as a TV movie – albeit a TV movie that has seen the inside of the Cannes Film Festival”s cavernous Grand Lumiere theater. The good news is that “Behind the Candelabra,” for all its seamy up-close intimacy, feels neither structurally nor formally compromised by the nurturing hand of HBO; it”s a biopic that bristles with life at the edges, luxuriating in the excesses of its personalities and production design alike.

In terms of content, meanwhile, the film”s televisual backing seems to have had an expanding effect. Soderbergh has remarked that he chose the small-screen path only because Richard LaGravenese”s script was “too gay” for theatrical film studios, and it”s certainly hard to think of a more forthright portrait of homosexual domesticity in mainstream cinema: it”s a film that takes sexuality as a given, all the better to magnify what”s genuinely queer about the sixtysomething Liberace”s relationship with gradually disillusioned young buck Scott Thorson.

While Michael Douglas”s shrewd, rude, wickedly funny turn as Liberace (known to his loved ones as Lee) is undeniably the star attraction of a film that, at least for its glitter-strewn first half, doesn”t stint on the seductive properties of camp, the story belongs chiefly to Scott, smartly played by Matt Damon as a stolid yet corruptible soul born of the foster-care system, who suddenly finds in the older man more family than either one can really handle.

Introduced to Liberace toward the end of the 1970s, with disco dying just as the AIDS crisis looms, Thorson”s sexual attraction to the bouffant-wigged showman is never far from a desire for the security of parental care; the rot sets in when Liberace takes this daddy complex to belief-defyingly literal levels. Under the principle-free knife of plastic surgeon Jack Startz (a frightening, hilariously hollow-eyed Rob Lowe), Scott is rebuilt in the less handsome image of his master; by the time formal adoption papers are drawn up, this relationship can bend no further without breaking.

Scott is sufficiently blinded by the lights (and what lights) to miss the obvious fact that his union with Liberace is a practised life cycle rather than a happy ending: when he enters the scene, he either can”t or won”t see the pricelessly bilious reaction shots of Lee”s outgoing boyfriend (Cheyenne Jackson). But he knows on which side his bread is buttered: in one of many ingenious shot choices by Soderbergh”s cinematographer alter ego Peter Andrews, the couple”s first kiss is shown in dignified long shot, framed by row upon row of expensive crystal glassware. It”s these material rewards that prove the sticking point when the couple eventually, inevitably exhaust their affections for each other in the film”s devastatingly exact final act, which bests last year”s “Keep the Lights On” as the most detailed, emotionally acute and sexually specific gay breakup story in recent film memory.

The film is too much fun – and ultimately, as Lee and Scott resort to the ugliest of ways to evict each other from their lives and minds, too raw-nerved – to feel much like social tract, but a cool-headed, universal advocacy of gay marriage prevails amid its flashy indulgence of this particular relationship”s peculiarities. Soderbergh and LaGravenese don”t shy from the tabloid salaciousness of the older man”s adoption of the younger, but the film it”s also posited as an extreme example of how social structures can be subverted, and potentially warped, if gay men are denied the right to conventional legal partnership.

Would the marriage have ended any less disastrously, in a dry hail of paperwork and stern lawyers” tones, had it been officially sanctioned? Probably not, given Liberace”s vampiric reliance on younger men as a kind of elixir. (“I”ve always had an eye for new and refreshing talent,” he says in one of LaGravenese”s most memorable exchanges, to which Scott”s priceless snapback is, “No, you”ve always had an an eye for new and refreshing dick.”) But as the hard-won tenderness of the film”s final moments suggest, homosexuals also have the right to end their relationships as ceremoniously as they begin.

Soderbergh”s knockout run of recent commercial films – “Side Effects” and “Magic Mike” chief among them – have highlighted his knack for slyly packing dangerous social and sexual politics into conventionally crowd-pleasing forms, so it”s no surprise that “Behind the Candelabra” gets this riskily subtextual within a structure that doesn”t stray far outside the parameters of the well-made Wikipedia biopic. “Well-made” is no veiled knock on its gorgeous craft, either: from Soderbergh alias Mary Ann Bernard”s crisp, witty editing to the tacky period splendour of the film”s extraordinary production and costume design to remarkable prosthetic work on the stars at all stages of the narrative, this is a reminder of just how invisible the line between television and theatrical production is these days.

Most of all, though, it”s Soderbergh”s ever-intuitive instincts over the manipulation of star power that make the film so vibrant. Casting Michael Douglas – established in such films as “Fatal Attraction” and “Disclosure” as a kind of bastion of well-oiled but faintly insecure heterosexuality – as America”s first camp icon (whether America knew it or not), is a stroke of genius. The actor, meanwhile, adds his own inspired touches with a performance that stops short of the all-consuming, transformative impressions that routinely impress awards voters, playing on his own onscreen prissiness. A star turn that”d be a shoo-in for an Oscar nomination if it weren”t primed to take every small-screen award from here until next spring, it”s the closest Liberace could ever have come to being a movie star himself.