Blades of gory in 'Machete'

Phil Collins put the case succinctly: It’s no fun being an illegal alien. Except if you’re “Machete,” an ex-Mexican federal agent disguised as a Texas landscaper with a bloody mission to mow down Minuteman types with his mighty array of gardening tools.

Writer-director Robert Rodriguez (who co-directs with his editor Ethan Maniquis) is on both sides of the line between clever and stupid in this badass Mexploitation flick, which sprang from a mock trailer contained in “Grindhouse.” Within the opening minutes, Machete (a psychotically entertaining Danny Trejo) has lopped the arms and heads off a dozen gangsters guarding the hideout of a Mexican drug lord — played by Steven Seagal.

Chased out of the country and across the border into Texas, Machete is hired by a shady businessman (Jeff Fahey) to assassinate a rabid state senator (Robert De Niro) who has been amping up the volume by denouncing illegals as “parasites,” complete with campaign commercials featuring creepy-crawly bugs. The businessman feels the senator has to be eliminated because he threatens to clamp down on the supply of cheap labor.

In his spare time, the senator turns vigilante with a sadistic Minuteman-like patrolman (Don Johnson) who enjoys driving along the border shooting any Mexicans they find sneaking into the country.

Any movie that finds a plausible reason to give Lindsay Lohan a nun’s habit and a machine gun is worth your attention, and Rodriguez’s fired-up mood about the politics of immigration gives “Machete” a full-throttle passion. As a comedy, it’s erratic — but it does contain one of the funniest lines you’ll hear at the movies this year: “Machete don’t text.”

The furiously funny finale, which is both absurd and absurdly violent, is not just wacky — it’s almost “The Naked Gun.” The scene swarms with bad hombres, naughty nurses, a chick in an eye patch and bikini top and Sister LiLo, who is otherwise frequently naked as the randy daughter of a political figure.

Most of the time, though, Rodriguez’s sense of humor is as blunt as the calluses on Machete’s hard-worked palms. He’ll never be more than a junior varsity Quentin Tarantino. The De Niro character, for instance, is a cardboard stooge that Tarantino would have wrestled with and built into something — a canny rival like the S.S. colonel in “Inglourious Basterds.” Tarantino would never have saddled his characters with political speeches about immigration nor settled for a gag as easy as a hired gun who advertises himself as 1-800-HIT-MAN.

Rodriguez can’t even be bothered with the workmanship of plotting. He hides behind the excuse that he’s simply being pure to the conventions of 1970s drive-in movies, but really he lacks the ability to string together a story. When he needs Machete to come up with irrefutable evidence against his foes, Rodriguez throws in a daft coincidence involving Machete’s hermano/padre — his brother (Cheech Marin), who is a well-armed priest.

As Tarantino has so frequently shown, fantasy violence can be comical, balletic, even rousing. In “Machete,” though, it’s so overdone — the whole movie looks like an explosion at the tomato paste factory — as to be cheapened.

After the endless limb-hacking and throat-cleaving of the early scenes, Rodriguez himself seems to feel things are getting a bit stale and advances into such new realms of bodily harm as crucifixion, weed-whacker attacks and barbed-wire electrocution. Too much, and it all amounts to too little. There’s a reason why “The Itchy and Scratchy Show” (the seeming inspiration for a scene in which Machete stabs a guy in the guts, then grabs one end of his intestine and uses it for a rope) runs for 30 seconds instead of 105 minutes.

Still, with his weatherbeaten face and ironclad expressions, Trejo is the real thing — an undocumented Clint Eastwood. The film he rules may be a weird combo of speechy and pulpy but it’s also what another all-star bloodbath, “The Expendables,” should have been — self-aware, flashy and fun.

kyle.smith@nypost.com