"The King of Comedy" fancies itself a scathing social satire about the lust for celebrity carried to extremes.

But ultimately, director Martin Scorsese's movie is a severely misconceived and distasteful study of delusional behavior. The truly maddening aspect is that Scorsese and his principal accomplices, writer Paul D. Zimmerman and actor Robert De Niro, cultivate an outlook as oblivious as the one they purport to scrutinize.

"King of Comedy" aggravates the problem it's supposed to illuminate. Far from clarifying the nature of a creepy social pathology, the movie assumes an attitude of smug, unjustified superiority toward every character in sight and the cockeyed spectacle of pop culture in general.

Opening today at area theaters, "The King of Comedy" was a script that kicked around for almost a decade. Zimmerman, who used to review movies for Newsweek, must have been inspired by Andy Warhol's witty observation that given the fleeting qualities of contemporary celebrity, someday everyone would be famous, for 15 minutes.

The absurdly named protagonist is overaged messenger boy Rupert Pupkin, played by De Niro. Pupkin threatens his idol, talk-show star Jerry Langford (Jerry Lewis in a hatefully conceived yet impressively sustained, slow-burn performance) with death to appear on his show performing the amateurish comic monologue he's been rehearsing for years.

Apprehended after the show for kidnaping Langford, the culprit tosses off the following crack to the arresting officers: "Better king for a night than schmuck for a lifetime." Obviously, the filmmakers couldn't resist putting their own tart commentary in the mouth of a character whose stupidity and self-righteousness disqualify him for such self-deprecating sassiness.

The rest of the world might readily agree that Pupkin was a schmuck. But the filmmakers think it's clever to pretend that a disreputable act of self-promotion transforms Pupkin into an overnight sensation and media darling. On the contrary, as Holly Golightly put it, "There are certain shades of limelight that can ruin a girl's complexion."

The key to the corrupted perception that undermines "King of Comedy" as a satire in any style,, is the bizarre notion that Pupkin's boomerang way of getting ahead and ingratiating himself would inevitably prove successful, even endearing. Given the circumstances depicted, there's no compelling reason to believe that Pupkin's shenanigans would earn him anything more than a lifetime of confinement under psychiatric supervision.

The movie's oddly ponderous, furtive tendencies suggest a far from confident operation. In retrospect, it appears that Rupert Pupkin was invented to expose a fundamental obliviousness in Scorsese and De Niro, because what they end up doing, as a practical matter, is endorsing the sort of delusion that inspired John Hinckley Jr. to impose himself on Jodie Foster.

Artists cannot be expected to anticipate or control every ramification of their work, but Scorsese and De Niro certainly knew how Hinckley's pathetic fantasies had been fed by their greatest collaboration, "Taxi Driver." At the very least, that should have made them peculiarly sensitive about any material that remotely paralleled Hinckley.

Although Pupkin is meant to be dismissed, in the last analysis, as a harmless celebrity-seeking nut, the movie never comes close to formulating a comic tone that might finesse the intimidating aspects of his pursuit of Langford. While the filmmakers seem intent on playing it dumb, they must have undertaken this ill-advised variation on their previous gallery of outlaw personalities in "Mean Streets," "Taxi Driver," "New York, New York" and "Raging Bull" with some awareness of placing themselves in a precarious and possibly disgraceful position.

There's a curious attempt to shift the physical threat away from De Niro's character to a subordinate nut: Sandra Bernhard playing a wealthy young idolater named Masha wants Langford to make love to her, and joins Pupkin, ordinarily a rival when shadowing their favorite celebrity, in his kidnaping conspiracy. The volatility that one customarily associates with De Niro's crazies is now the outstanding aspect of Bernhard's character, an ugly young woman who suggests an aptitude for unpredictably ugly outbursts.

It's easy to imagine dying from boredom as a direct consequence of Rupert Pupkin's self-centered prattling and pestering, and the movie itself seems to expire repeatedly by allowing De Niro prolonged opportunities to emphasize that numbing boringness. In fact, you can almost feel the movie deflate during an early sequence where Pupkin dates an old high-school crush (the lovely Diahnne Abbott, who was once married to De Niro) and yammers on unmercifully about his nonexistent show business connections.

Perhaps it's the essential hypocrisy of their attitude toward the protagonist that accounts for the blanket condemnation of every character unlucky enough to make Pupkin's acquaintance. Langford, presumably modeled on Johnny Carson, is portrayed as an icy loner, and the only overt act of violence is reserved for him--a gratuitous knockout punch thrown at Masha after he frees himself. This malicious touch seems to fudge the issue of the kidnapers' culpability; even if it pleases the filmmakers to identify Langford as a cruel man, there's no escaping the fact that he remains the injured party in this situation.

In a similar respect, the Diahnne Abbott character suffers a mean little touch: embarrassed when she accompanies Pupkin to Langford's Long Island residence and discovers that they're uninvited, she steals a knickknack. It doesn't seem in character, but it conforms to a compulsive streak of nastiness in the writing and direction. The same thing is true of the suggestions that Pupkin scores a big hit on Langford's show and gets more magazine covers than Dustin Hoffman's character in "Tootsie."

It's unlikely that a mass culture twice as craven and undiscriminating as ours would really dote on the exploits of Rupert Pupkin. This exaggeration is necessary only for filmmakers obliged to hide behind the argument that the culture never discriminates. THE KING OF COMEDY

Directed by Martin Scorsese; written by Paul D. Zimmerman; production designer, Boris Levin; music production by Robbie Robertson; produced by Arnon Milchan for 20th Century-Fox. This film runs 120 minutes and is rated PG. THE CAST Rupert Pupkin . . . Robert De Niro Jerry Langford . . . . Jerry Lewis Himself . . . Tony Randall Rita . . . Diahnne Abbott Masha . . . . Sandra Bernhard