The main question "Under the Same Moon" poses is whether its story, which follows the basic outline of a separated mother and son fairy tale, befits its subject, the plight of illegal Mexican immigrants. The immigration issue has in the last few years become a hot one in part due to economic angst and homeland security paranoia, but Mexican director Patricia Riggen and screenwriter Ligiah Villalobos don't use their film to explore the larger political picture of fence-hopping workers and the varied American responses to their increasing numbers. Instead "Under the Same Moon" remains at ground level, showing audiences the unique backgrounds of individuals forced by circumstances to leave their homes and risk their lives north of the border.
The problem with "Under the Same Moon," then, is that while many of its characters can conceivably represent these real people toiling in the undocumented shadows far away from their families and communities, its protagonist, nine-year-old Carlos (Adrian Alonso), does not. His journey from a small Mexican town to Tucson to East Los Angeles in search of his illegal alien mother, Rosario (Kate del Castillo), might be possible, but realistically it's only the stuff of heartstring-yanking melodrama. That doesn't mean there isn't room within "Under the Same Moon"'s predictable trajectory for a few surprisingly effective emotional moments, but the film as a whole betrays the somber authenticity of its subjects' dire situations with unbelievable and sentimental contrivances.
In the first place it takes an extreme suspension of belief to buy Carlos's motivation and means in seeking out mommy (who works as domestic help for an L.A. rich bitch so she can send money back home): because he misses her, because his maternal grandmother and guardian dies, because a young collegiate Mexican couple, legal American citizens portrayed as overeducated sell-outs, take the child's saved-up cash with little reservation to transport him past customs. Needless to say, Things Go Wrong and Carlos finds himself prey to danger. Abducted by a junkie and almost sold to a pimp, he's luckily rescued by a Mexican woman whose home serves as a refuge for illegals; when the industrial greenhouse he briefly works in is raided by the IEA he's left (after a close escape) in the company of Enrique (Eugenio Derbez), a grouchy loner who at first begrudges Carlos the adorable burden he presents.
It's Odd Couple time! Enrique plays reluctant surrogate father and companion to Carlos, and it's the burgeoning bond between the lost boy and the world-weary man that becomes "Under the Same Moon"'s greatest, if still cliched, strength. While Rosario loses a job (all the film's Americans are heartless rich snots, depraved drug addicts, or the police) and is forced to marry a legal Mexican for security, scenes like the one where Carlos and Enrique combatively duel to a radio song while washing dishes in a restaurant kitchen provide not unpleasant comic relief.
Does Carlos eventually reach his mom? Let's just say that if you've never seen a movie before you'll be happily astounded by the film's conclusion. "Under the Same Moon" may be a bright, peppy, and unabashedly saccharine "humanistic" take on immigration, but, plagued by undeveloped social criticisms, idiot-aimed exposition, and uninspiring performances (Derbez aside), it constantly reminds its audience why such an approach is far from satisfactory.