It was inevitable that when “The Purge” became a modest success last year, a sequel would soon follow. And so we get this misfire, in which writer-director James DeMonaco expands the scope of his debut feature with the result that whatever intensity the original derived from its claustrophobic setting is dissipated. For a movie with this subtitle, “The Purge: Anarchy” is a surprisingly humdrum affair, notable only for the mixed messages it manages to deliver along its corpse-strewn route.

The first “Purge” was essentially a home-invasion movie predicated on a nutty premise. In the near future the United States has come under the dominion of a new group of “founding fathers” who control the citizens’ propensity for violence by permitting them a single night each year to give full rein to it without any consequences. Those not wanting to be “purgers” or their victims hole up for the night, hoping to survive the slaughter that weapon-wielding maniacs intend to inflict on anybody they encounter. The policy, we’re told, has another benefit—since the victims are the marginalized members of society, it cuts down on the number of those who aren’t productive contributors to national wealth.

The first “Purge”—an unfortunate title that makes the whole operation sound like a societal enema—saw Ethan Hawke trying to save himself and his family from a bunch of masked creeps who’d found their way into their heavily-fortified house. In it DeMonaco appeared to be attempting to mimic the enclosed-space tension that the young John Carpenter pulled off so brilliantly in “Assault on Precinct 13” (the pretty good 2005 remake of which was scripted by DeMonaco and also starred Hawke); and while he didn’t match his model, at least the effort showed promise.

This time around DeMonaco’s going for the broader canvas that Carpenter, again, nailed so successfully in “Escape from New York,” and he fails signally at it. His Snake Plissken-style hero is the enigmatic Sergeant (Frank Grillo, looking rather like a refugee from a non-Equity tour of “Grease”), who ventures out on purge night in his souped-up car armed to the teeth on a mission that will be revealed only at the picture’s close. Coming upon a truck presided over by a brutal purger called Big Daddy (Jack Conley), who’s using an army of SWAT-type minions to capture the mother-daughter team of Eva (Carmen Ejogo) and Cali (Zoe Soul), he reluctantly rescues not only the women but a young couple, Shane (Zach Gilford) and Liz (Kiele Sanchez), whose car had been sabotaged by a masked bunch of thugs. Together the five must make their way through the streets, avoiding Big Daddy’s soldiers as well as the other purgers they encounter. Meanwhile Carmelo (Michael K. Williams), a Black Panther type who broadcasts inflammatory messages about how the purge strengthens the establishment at the expense of the weak and poor, leads an armed resistance against the whole night of massacre.

The Carmelo subplot is only one of the script points that hammer home an “anger at the elites” message intended to appeal to the audience’s understandable animus against the privileged and powerful in today’s America—there are even periodic references to income inequality to drive the idea into the ground. Another involves Eva’s ill father (John Beasley) who sells himself to a rich family as a sacrifice, while yet another comes near the end of the movie, when our little band falls into the hands of a bunch of well-to-do types, presided over by a snooty old auctioneer (Judith McConnell), who bid for the right to hunt and kill them. This episode, which tries for a sense of surrealism it never achieves, pales in comparison to the similarly off-the-wall, but far more literal, portrayal of the rich feeding off the poor in Brian Yuzna’s wacky but oddly effective 1989 satire “Society.” A final twist involving Bid Daddy also falls flat, but at least it helps to explain why the streets of Los Angeles boast so few purgers as well as victims—a circumstance which in all likelihood actually resulted from a pinched budget.

Then there’s the weaponry. “Anarchy” preaches again and again about how awful the implements of death being used by purgers are, but that message is upended by its virtual glorification of gun violence, and by the fact that it seems to have no trouble ogling Sergeant as he straps on his arms, “Rambo”-style, or cheers on Carmelo and his resistance fighters as they blast away at their well-heeled opponents. And in the end, it’s a gun that saves the day when it appears that Sergeant, who finally refuses to resort to vengeance, will bite the dust. All of that points up the central problem of the “Purge” movies—DeMonaco apparently wants to say something about the ills of American society, but gets so tangled in his need to pander to the expectations of the action audience while doing so that whatever message he has in mind gets all muddled in the telling.

Performances are negligible in this sort of movie, but Grillo does a passable impression of a standard-issue tough but sensitive guy, and Gilford and Sanchez get by as a callow couple, even though their fate will be obvious to anybody who’s ever seen a movie from their first appearance. By contrast Ejogo overdoes the weepy damsel-in-distress routine, and Soul is so wearyingly obnoxious as her daughter that you almost wish she’d get bumped off early. Conley does a poor R. Lee Ermey imitation as the nasty Big Daddy, and an odd interlude featuring Eva’s co-worker Tanya and her family gives Justina Machado an opportunity to mercilessly chew the scenery.

Technically the picture looks pretty poverty-row, but cinematographer Jacques Jouffret does what he can with the perpetually dank images, though editors Vince Fliippone and Todd E. Miller’s pacing—which aims to be atmospheric but comes across as merely lethargic—doesn’t help. Nor does Nathan Whitehead’s score, which, with its clippety-clop motif, resembles the special effects track from an old western radio show; the occasional interruptions by what sound like a couple of garbage-can covers crashing together are no more effective.

“Anarchy” obviously closes with an invitation to another installment. (It’s set in 2023, but a clip featuring a government leader suggests that the installation of his regime—and presumably the introduction of the “purge” method—came with their election nine years earlier, in 2014. Is this supposed to represent the triumph of the Tea Party?) Let’s just hope the series doesn’t become as much an annual affair as the cheerless slaughter it depicts.