LOS ANGELES — Considering he struck comedy gold with “Meet the Parents” before successfully entering the cable political arena with “Recount” and “Game Change,” director Jay Roach would seem to have been the ideal guy to be steering “The Campaign.”

But even though leads Will Ferrell and Zach Galifianakis are amusingly on point as a pair of mud-slinging contenders for Congress, the platform is a wobbly political satire that flip-flops chaotically between clever and crass, never finding a sturdy comedic footing.

With its election-year timing and the scarcity of R-rated fare that at least looks like it should be fun, the Warner Bros. release might encounter some initial traction, but, clocking in at a tellingly insubstantial 85 minutes, it likely will see sharply falling approval ratings.

Ferrell’s Cam Brady is a slick, incumbent Republican congressman who’s fully expecting the upcoming election to be yet another cakewalk, given that he’s running unopposed.

But when Brady dials a wrong number, leaving a crude message meant for his mistress, a pair of corrupt power brokers called the Motch brothers (John Lithgow and Dan Aykroyd) see an opportunity in the widely exposed gaffe.

Looking to get the necessary tax-exempt backing for their insourcing scheme — importing cheap Chinese labor to work in their North Carolina factories — they find a patsy in the form of naive tourism center director Marty Huggins (Galifianakis) to run against Brady on a family values manifesto.

Taken under the wing of Tim Wattley (Dylan McDermott), a highly disciplined black op of a campaign manager, Huggins is transformed from fey family black sheep to tough-talking, viable opponent, setting the stage for a no-holds-barred, mean-spirited race.

On paper, given the players and the potent milieu, “The Campaign” should have been a slam dunk.

Unfortunately, to borrow Huggins’ campaign slogan, “It’s a mess!”

The script, by Chris Henchy (“The Other Guys”) and Shawn Harwell, from a story also contributed by longtime Ferrell collaborator Adam McKay, is lazily hit-and-miss, neither sufficiently sharp nor substantial to bring anything fresh or consistently entertaining to the political satire genre.

While it probably would have made a terrific series of “Funny or Die” shorts, the film comes up notably short as a feature proposition, with an abrupt ending that smacks of last-minute cutting.

And though Ferrell and Galifianakis make for lively opponents, it’s not like we haven’t seen them play these guys before.

Ferrell’s Cam has more than a bit of the smugness of his famed George W. Bush impersonation (with a smarmy John Edwards-type overlay), while Galifianakis’ Marty is a slight variation on his twin brother Seth Galifianakis character he often has portrayed in short segments and onstage.

Providing reliable support are Sarah Baker as Huggins’ sweet, shoved-to-the-sidelines wife and Jason Sudeikis as Brady’s long-suffering campaign manager.