Joel and Ethan Coen are clever fellows in more ways than one. When then pen a really good script, they direct it themselves. When an effort turns out to be mediocre, they pass it along to somebody else. That’s the case with George Clooney’s “Suburbicon,” a misfire in virtually every respect.

The screenplay is basically a film noir spoof of the sort that the brothers managed so well in “Blood Simple” and “Fargo.” Unfortunately, it’s ineptly handled here. That overarching plot, however, is—at least in this version, which is also credited to Clooney and his writing partner Grant Heslov—combined with a story about opposition to racial integration in the late 1950s. The two halves are meant to comment on each other—familial duplicity juxtaposed against the larger context of social discord—but the two, unfortunately, aren’t effectively blended.

The domestic side is anchored by little Nicky (Noah Jupe), the adolescent son of Gardner and Rose Lodge (Matt Damon and Julianne Moore), who live in the sterile, candy-colored but lily-white planned titular community, clearly modeled on Levittown and its imitators. Blonde Rose is in a wheelchair as the result of an auto accident in which Gardner, an executive in a financial firm, was driving.

Rose’s twin but dark-haired sister Margaret (also Moore) is visiting when the house is invaded by a couple of quietly menacing intruders (Glenn Flesher and Alex Hassell), who tie the family up before chloroforming them. Ruth dies as a result of the assault, and Margaret moves in with Gardner and Nicky to help them over the rough patch.

But all is not as it seems, since when given the chance Gardner fails to identify the perpetrators in a police line-up. Meanwhile Margaret has dyed her hair blonde to look like Ruth. Even Nicky’s raucously gregarious, good-natured uncle Mitch (Gary Basaraba) can’t do much, though he’s concerned about what’s happening. This is basically told from Nicky’s point of view—rather like in Bob Balaban’s underappreciated dark comedy “Parents”—though, of course, there are plenty of scenes outside his immediate perspective (and no intimations of cannibalism, expect perhaps of a metaphorical sort).

Simultaneously the neighborhood is wracked when an African-American couple, the Meyers (Leith M. Burke and Karimah Westbrook), along with their son Andy (Tony Espinosa), move in next door, their backyard abutting the Lodges’. The outrage of virtually the whole town is immediate, and before long the residents have become an angry mob trying to drive the Meyers out—ultimately with a gruesome spasm of violence. The sole saving grace in the mayhem is that Nicky and Andy become friends.

The sad truth about “Suburbicon” is that neither of the two major plot threads works. Apart from Nicky, nicely played by Jupe, the entire Lodge story is pretty much a bust. Gardner is little more than a poor cousin to William H. Macy’s inept Jerry Lundegaard from “Fargo,” and Damon plays him as a dull, lethargic fellow, while Moore makes surprisingly little of her dual role. The remainder of the cast, while adequate, isn’t a patch on the colorful performers with whom the Coens filled the films they directed on their own. Oscar Isaac brings things briefly to life as a smooth-operating insurance agent, but the promising “Double Indemnity” subplot peters out quickly, and a series of twists in the last reel feel formulaic, at least as staged by Clooney.

And that’s the fundamental problem with the picture. Other comedies that have played off film noir—including those penned by the Coens—were done up with some style. Think of what Danny DeVito managed with “Throw Momma from the Train,” or Jim Abrahams and the Zucker brothers with “Rotten People.” Neither was of the quality of “Fargo,” but both were enjoyable because they were staged with energy and verve. By contrast Clooney’s work is stodgy and pedestrian; he’s unable to make the obviously goofy parts funny or even quirkily engaging, and can’t achieve a proper balance between dark humor and simple unpleasantness in the grimmer episodes. Tonally the picture is a mess rather than a satisfying blend of disparate moods.

There is some pleasure to be gotten from the technical side of things. James D. Bissell’s production design and Jenny Eagan’s costumes are high-glow fifties period, complete with clips from old TV shows and metal children’s rides outside the local supermarket (with its racist manager). Robert Elswit’s camerawork casts everything with a glow, even when it’s not terribly appropriate. And Alexandre Desplat’s score works overtime, switching from style to style in a rather desperate attempt to mesh with the movie’s shifting moods.

The effort is wasted, though, in view of the lumpy, misshapen script and clumsy direction. Perhaps the Coens, or Tim Burton, could have molded “Suburbicon” into a winning blend of dark comedy and old-style thriller. Clooney doesn’t.