It might be one of the first films conceived as a trailer and later expanded into a feature. Machete, Robert Rodriguez’s story of a Rambo-like ex-Federale betrayed by his bosses and out for revenge, began as a tongue-in-cheek teaser for Grindhouse, the director’s 2007 homage to ’70s exploitation fare. But it soon evolved into something more.

“Once we made the trailer, I thought that was as far as it was going to go,” says Rodriguez, 42, who cast cousin and longtime friend Danny Trejo as the titular tough guy at the center of his cheerfully gruesome thriller, which opened Friday.

“But it got such a huge reaction – people kept asking for it. The cast came together, the story kept getting better, and the whole thing took on a life of its own.”

That, and Trejo kept on him. “I wanted him to write the script,” says the 66-year-old actor, who has played supporting roles in six prior Rodriguez productions, including Spy Kids (2001), in which his Machete character first appeared, and two sequels. “I’d call him all the time. You know, ‘When are we going to do Machete?’ I must have asked him that thousands of times. I was ready.”

Trejo, a veteran of more than 50 movies who spent his formative years in and out of jail, becoming a prison boxing champion during 18 months at San Quentin, had never enjoyed top billing. (He will be featured prominently, however, in next year's A Very Harold & Kumar Christmas and Death Race 2.) For Rodriguez, Machete, the distant offspring of an idea the two first discussed as far back as 1995’s Desperado, was the perfect vehicle to change that.

“Everybody’s had Danny in their movie before,” he says of the man who, in his words, has made the transition “from ex-con to icon.” “Steven Seagal has killed him a few times. Robert De Niro put a bullet in his head in Heat. Now it’s time for Danny to return the favor.”

Seagal and De Niro, along with Michelle Rodriguez (no relation) and Jessica Alba, are just a few of the marquee talents who form what the director calls a “dream cast,” made possible, he says, by “De Niro, back in Goodfellas mode.” That they joined him for Machete, one of his most personal projects to date, is icing on the cake.

“When I first started in the business, something like this didn’t seem possible,” the Mexican-American director says. “But look at the response the Machete trailer got from everyone, not just Latins.

“Nobody wants to go see just a Latin movie, not even Latins. They don’t want to feel like a side group, they want to be part of world culture. But with Machete, you can go out and see Latin superheroes on the screen. And if you’re not Latin, you get great entertainment with a different flavor than you’re used to.”