Last March, on the first night of the 2010 South by Southwest Film Festival, a couple hundred journalists, bloggers, and moviegoers filled every seat at the Alamo Drafthouse Ritz, in downtown Austin. They had come to see Robert Rodriguez, or more precisely, scenes from the Rodriguez-produced, Nimród Antal-directed Predators, which had been shot mostly in Austin at Rodriguez’s Troublemaker Studios and which would be released a few months hence. First, Rodriguez screened the trailer for the film. Then, as if this were an Introduction to Film Studies course and we were collectively teasing out the hidden meanings in D. W. Griffith’s Intolerance, he screened a second, almost identical version of the same trailer. Later came questions from the crowd, each more picayune and nerdy than the last (would there be references in this new film to the original Predator? Might Arnold Schwarzenegger make a cameo?). Later still, the filmmaker invited everyone to form a line and observe the famed Predator head up close. The fanboys in the room gazed upon this prop with more reverence than would be afforded the crown jewels and the Shroud of Turin combined.

If you missed Predators when it opened, in July, count yourself lucky. A charmless replay of The Most Dangerous Game, starring a strangely juice-headed Adrien Brody, it didn’t so much reboot the eighties sci-fi franchise as drive a final nail into its coffin. If, however, you’ve been wondering what’s gone wrong with Rodriguez, a filmmaker whose ecstatic debut feature, El Mariachi, is partly credited with giving birth to the American indie renaissance of the nineties, well, you’re not the only one. The Predators presentation in March was hardly the first sign that he had slipped down a rabbit hole of juvenile arcana; the problem was already well afoot when he and Quentin Tarantino convinced themselves, in 2007, that the universe was clamoring for Grindhouse, a postmodern homage to seventies exploitation flicks. But watching this grown man discuss the finer points of a cheesy alien thriller as if our national security were at stake brought matters into depressingly stark focus. Rodriguez has another movie opening this month, Machete, an expansion of a faux trailer he made for Grindhouse, and the early controversy it has stirred, after the director released another trailer suggesting the movie was some sort of pro-immigration tract, at least offers a glimmer of hope. But these days it’s looking more and more as if a filmmaker who for so long had his finger on the pulse of the zeitgeist has become irrelevant.

Irrelevant, but still bursting with potential. The thing about Rodriguez is that he clearly “gets” it, in a way most contemporary directors do not; he intuitively grasps where the popular culture is headed long before it gets there. Consider Spy Kids 3-D: Game Over (2003), which—six years before James Cameron’s Avatar—anticipated our current craze for 3-D effects. Unfolding within the confines of a video game within the story, Spy Kids 3-D strove to create a tactile, fully immersive viewing experience; you can draw a direct line from it not just to Avatar but also to Christopher Nolan’s Inception and M. Night Shyamalan’s The Last Airbender, to cite two of this year’s bigger successes. In 2005, in collaboration with Frank Miller, Rodriguez made Sin City, a violent fantasy shot in monochromatic blacks and whites with occasional blasts of neon color. The storytelling was emotionally uninvolving, but this film too seemed to invent a new filmic language. It remains among the most convincing renderings of a graphic novel ever brought to the screen.

Yet it’s one thing to anticipate a trend and quite another to shape and define it—that’s what separates a Steven Spielberg and a Peter Jackson from, say, a Joe Johnston (Jumanji) and a Shawn Levy (Night at the Museum). The dirty little secret about Rodriguez, one that doesn’t often get mentioned in these parts, probably because his productions continue to pump so much money into the Texas economy, is that his movies in recent years have gone from borderline unwatchable to plainly dreadful (or maybe it’s the other way around). Who’s going to credit the deafeningly shrill Spy Kids with resurrecting 3-D when you can barely sit through it without swallowing two Advil? Nor has Rodriguez shown the necessary patience to allow his ideas to fully flower and turn into something enduring. The technology employed in both Spy Kids and The Adventures of Sharkboy and Lavagirl 3-D (2005) was a witty retro goof—cardboard glasses, one eye tinted red, the other blue—but he never attempted to push it to the next level, à la Cameron or the Pixar animators, and develop genuinely three-dimensional artificial worlds. (He abandoned 3-D entirely, along with good sense and anything resembling a plot, in his most recent children’s picture, 2009’s Shorts.) And whereas directors like Zack Snyder (300) and Nolan (The Dark Knight) heard the clarion call of Sin City and further blurred the lines between comic books, literature, and cinema, Rodriguez has been content lately to just spin his wheels, setting up still more sequels and reboots. After developing and then abandoning a remake of Barbarella and a live-action version of The Jetsons, he’s presently attached to Spy Kids 4 and Sin City 2.

The real bummer of all this: Rodriguez doesn’t seem to care that his work no longer matters. The party line on him is that he makes his movies cheaply, ensuring that they’ll generate some kind of profit, which in turn allows him to work on whatever projects he pleases and remain living in Austin. That’s a laudable enough goal, but isn’t Rodriguez also selling his talent short? For a brief moment in the spring, it appeared otherwise, when his trailer for Machete, which he issued as “a special Cinco de Mayo message to Arizona,” suggested the movie is about a Mexican man hired to assassinate an anti-immigration United States senator (“They just f—ed with the wrong Mexican,” the voice-over brazenly tells us). Was this famously mild-mannered filmmaker about to step into the morass of immigration policy debate? Um, not exactly. Because a week or so later, when a number of conservative bloggers raised questions about whether Machete portrayed Texas in a negative light and thus should be disqualified for state production incentive funding, Rodriguez backed down, telling Ain’t It Cool News’s Harry Knowles that the trailer was an elaborate goof. The real story, in fact, is a slightly more conventional-sounding tale of a Mexican man (Danny Trejo) seeking revenge against the drug lord (Steven Seagal) who killed his family. (As of mid-July, there was still no determination about whether the film would qualify for incentive money, though it’s unlikely that the Texas Film Commission will do anything to alienate the state’s most prolific director.)

Granted, nobody wants or expects Rodriguez to turn into an earnest Ben Affleck-style do-gooder. But wouldn’t it have been curious to see this director use the puckish visual wit to make people uncomfortable, to challenge preconceived notions about the immigration issue, to assert that even the schlockiest exploitation fantasy might have social relevance? Instead, in that same interview with Knowles, Rodriguez dismisses his own political opinions (“I’m putting myself to sleep [talking about this]”) before going on to detail yet another nerdtastic project he has in the pipeline, a remake of the 1983 animated fantasy Fire and Ice.

Knowles asks of this upcoming movie, “Does this mean we’ll get . . . subhumans and pterodactyl-riding barbaric warriors?”

Rodriguez’s response: “Yes! You bet. It’s that kind of awesome.”