Thank You for Smoking “You know what’d make you feel better? A cigarette!”

All right, can we just agree that at this point, everyone knows what cigarettes do? We've seen the tarred-up lungs and heard the wheezing coughs—but the sanctimonious anti-smoking crew keeps yammering away, endlessly repeating scary statistics as they push through anti-smoking laws. They're enough to make even a non-smoker like myself start thinking in a pro-smoking light—a creepy thought that, at least in part, contributed to my excitement for Thank You for Smoking.

Which, by the way, starts off great. Nick Naylor (Aaron Eckhart)—a spin doctor for Big Tobacco—is on a talk show, defending cigarettes against a slew of activists and a hairless kid, a casualty of smoking that Naylor dubs "Cancer Boy." At Naylor's introduction, the audience boos and spits; minutes later, the oily-tongued Naylor's shaking hands with a grinning Cancer Boy and basking in audience applause.

Smoking—which follows the unscrupulous Naylor as he spins his way through activists and accusations—has a great premise. Naylor's best friends (Maria Bello and David Koechner) represent the booze and gun industries; over drinks, they compete over whose industry causes the most deaths. Meanwhile, Naylor spars with a Birkenstock-clad Vermont senator (William H. Macy) and hooks up with a reporter (Katie Holmes), admitting he has no qualms about his job—he does it to pay the mortgage. And disconcertingly, the perfectly cast Eckhart's smarmy smugness and deft delivery keep the ethically challenged Naylor utterly charming. (It helps that Eckhart's backed up by a great cast, including Robert Duvall, J.K. Simmons, Adam Brody, and Rob Lowe.)

But like all wannabe cynics, director Jason Reitman—who also adapted the screenplay from Christopher Buckley's novel—can't maintain Smoking's tone for long. Midway through, Smoking takes a turn for the banal, the razor-sharp satire of the first 45 minutes giving way to a more scattershot type of comedy. Gone are the incisive, uncomfortable jabs at both corporations and consumers, replaced with vague developments that feel weak and confusing. By the final reel, Naylor is dividing his time between pimping cigarettes and wondering about how well he's raising his kid—and the audience is left wondering where the film's clever, dark, fearless charm went. Sure, this neutering of Smoking's amorality is better for its characters' consciences and lungs—but it kills Smoking's smart fun faster than a three-pack-a-day habit.