“Blow” has all the makings of a great film: good directing, a powerful true story and a strong ensemble cast — yet in the end, it fails to measure up to its potential.

The film begins with a flashback to the childhood of the story’s protagonist, George Jung, played by Johnny Depp (“Chocol?t,” “Before Night Falls”). The director, Ted Demme (“Life,” “Beautiful Girls”) shot these extensive scenes in Fuji special stock film, which gives the colors a vibrant look and revisits an ethereal childhood.

Jung’s parents — Ray Liotta (“Heartbreakers,” “Hannibal”) and Rachel Griffiths (“Hillary and Jackie,” “My Best Friend’s Wedding”) — are hard-working yet barely able to get by. These money worries motivate Jung to never be poor, no matter what.

Hence, Jung moves from New England to the new Eden, Manhattan Beach, Calif. “Boston George” becomes the premiere pot dealer for the beach city after he meets his first partner Derek Foreal, dynamically played by Paul Reubens (“Mystery Men,” “Pee-wee’s Big Adventure”). Foreal is a colorful gay hairdresser who becomes the epitome of a networking drug dealer, supplying the entire West Coast with pot and then cocaine. (“Start with the rock stars and actors and the rest of the country will follow.”) As Jung sees exactly how much potential drugs have, he expands his distribution to the drug-starved East Coast.

Jung establishes several simple, yet successful ways of smuggling drugs. Though neck deep in the seamy life of drugs, Jung remains gregarious.

The first two-thirds of the film do a great job of presenting the drugs-to-riches story. At one point, Jung and his second partner Diego (Jordi Molla) are in an apartment filled to the ceiling with millions of dollars.

PenÇlope Cruz (“All the Pretty Horses,” “Woman on Top”) plays Jung’s first wife who starts out as a mustang of a woman, but deteriorates into a hateful virago; it’s surprising to watch since she is usually so irresistible. Jung’s daughter, Kristine’s (Emma Roberts) performance is heartbreaking, yet cliched.

Essentially, cliches are what bring this movie down. Jung rises and falls from “paradise” and “perfection” so many times that by the end we just don’t care. Essentially, Demme is merely trying to convince us of what we already know … that a life of illicit drug smuggling is bad.

The ’70s scenes are a blast to watch, but all that fun doesn’t make up for a general lack of originality in this film.