After the huge amount of weaponry shipped to other nations in the world, perhaps the worst US export nowadays consists of political consultants who debased American elections with their unsavory methods and are now busily engaged in doing the same in foreign climes. Their baleful influence is the subject of “Our Brand Is Crisis,” an effortful picture that doesn’t do justice to its promising premise either as comedy or as drama.

The picture, written by Peter Straughan, is a fictionalized version of a similarly-titled 2005 documentary by Rachel Boynton about the 2002 presidential election in Bolivia. In that campaign, James Carville worked on the staff of Gonzalo Sanchez de Lozada, who had been president in the mid-nineties. Lozada was elected over populist Evo Morales but resigned the following year (Morales later became president in 2006; interestingly, Lozada is explicitly mentioned here as a former president.)

In Straughan’s revision, the Carville character is ”Calamity” Jane Bodine (Sandra Bullock), a burned-out consultant who has retired to a remote cabin after a succession of defeats and what was apparently a nervous breakdown; she makes pottery to maintain her equilibrium. (Interestingly, the character was originally written as a role for George Clooney, one of the producers.) She’s visited by Nell (Ann Dowd) and Ben (Anthony Mackie), a couple of consultants working for Pedro Castillo (Joaquim de Almeida), a senator who was once president but is running well behind several other candidates, most notably a populist named Rivera (Louis Arcella). She agrees to lend a hand, but upon her arrival in Bolivia suffers a prolonged bout of nausea caused, it’s said, by the altitude, though it might as well be the result of her candidate’s blasé attitude. She looks, frankly, a bit like somebody who’s wandered in from the set of “The Walking Dead.”

Her mood isn’t improved by the revelation that Rivera has a US consultant, too—and it’s Pat Candy (Billy Bob Thornton, physically channeling Carville), her nemesis. It’s not until Castillo is the target of a egg attack by a protestor and responds by punching him that Bodine springs to life. That spontaneous burst of energy on the candidate’s par energizes Bodine as well: she sees a way of positioning him as a fighter at a time of crisis, and that becomes the campaign’s theme. It also brings her into a series of direct confrontations with Candy as the two old enemies trade dirty tricks and acerbic insults (the ultimate example coming in the form of a wild chase down a mountain road by competing campaign buses).

The picture is obviously intended to be a sharp satire, but for the most part it’s an oddly muted one that occasionally switches to rambunctious slapstick and more often veers into soapy drama, not only in its saccharine treatment of a young Castillo volunteer, Eduardo (Reynaldo Pacheco), whose idealism suffers a cruel shock in the end, but in its bookending interviews with Jane herself, for whom, it appears, the campaign becomes a road-to-Damascus moment. On the one hand it’s laudable that a major-studio film should risk being different from the pack; the shifting tones are evidence of its ambition—and probably of the influence of director David Gordon Green, whose previous pictures have taken similar chances, sometimes successfully and sometimes not. In this case, unfortunately, the risk doesn’t pay off. Instead of being tantalizingly disarming, “Our Brand Is Brand” simply comes across as messy and disjointed.

Still, one has to give Straughan and Green points for effort, even though the result falls short. The same is true of Bullock, who’s playing a character as mixed-up as the movie she’s in. Dour and drab at one moment and a bundle of ferocious energy the next, cunning but with a deeply vulnerable side, Bodine is a complex figure, and Bullock wrestles to make her comprehensible. She doesn’t fully succeed, because frankly the script doesn’t reveal enough of her background to allow for that, but at least she’s not a cookie-cutter heroine or villainess, and Bullock gets across the ambiguity. Thornton slides slickly through another Mephistophelean role—even alluding to the devilish figure at one point, and Almeida, too often stuck playing drug dealers, seems to enjoy playing a person of stature for a change, even if Castillo is hardly an unalloyed good-guy. The remainder of the cast, especially Mackie and Dowd, feel underused, though Scoot McNairy and Zoe Kazan have their moments as other members of the Castillo brain trust. And Arcella strikes the right pose of empty populism.

One of the strongest points of the picture are the locations; the backgrounds look genuinely authentic because most of them are, and cinematographer Tim Orr takes full advantage of the local color they provide. The other technical credits are unostentatiously solid.

In the end, though, “Our Brand Is Crisis” is a film with a great deal of potential that doesn’t quite gel. Interesting but ultimately unsatisfying, it has to be categorized as a near-miss.