Five summers have passed since The Purge launched a savagely entertaining, unexpectedly profitable franchise. Given how times have a’changed since then, it feels like a hard, hard 15.

Far more than countless, toothless YA series purporting the same, the Purge films established believable oppression and outrage, along with the outer limits of laying your body down for either side of its hypothetical conceit — an annual 12-hour Purge during which all crimes, up to and including murder, are legal to allow catharsis for society’s worst instincts. Say what you want about the blunt-force crudity of writer-director James DeMonaco’s work on this franchise; he has known the bloody tint of history’s ink and the thick pulp on which it is often printed.

The first film’s nonpartisan slant played like a worst-case compromise from all possible political factions. At the end of 2016’s The Purge: Election Year, a female POTUS terminates the Purge and reveals it as a mere smokescreen for predatory capitalism and genocide to cull minorities and the poor. The bad guys, a political alternative known as the New Founding Fathers of America (NFFA), were a conservative movement cloaking craven, cowardly behavior in a tight Pentecostal swaddle. It was a worthwhile spit in the face. It also felt like a natural endpoint.

But boy, it feels downright irresponsible to just end this franchise in the era of “Oh, Fuck … What Now?” Thus, The First Purge … and on the cynically jokey release date of July 4, no less.

This prequel presents the Purge at its pupa stage in our present day — known as “The Staten Island Experiment” and a trial run for the NFFA to gauge depravity with which it could get away under the guise of doing “whatever it takes to let you dream again.” Citing policies of scientific study rather than carrot-and-stick and funded by the National Rifle Association, the NFFA offers $5,000 to anyone even willing to stay during the 12-hour stretch. But this is a pay-to-slay scenario. The more you participate, the more they’ll compensate.

DeMonaco wrote this installment but hands directorial duty to African-American filmmaker Gerard McMurray. We’ve rolled with white heroes as iconographic stand-ins for ass-kicking liberalism. The First Purge’s most famous face is white; Marisa Tomei has a throwaway role as the social scientist behind the experiment, barely staying awake through lines like “Basic tenets of morality have to be abandoned and religious dogma must be dropped. But DeMonaco and McMurray focus on black and brown faces with initially poignant powerlessness to push back.

This shift also represents a fine forum for fledgling talent to flourish in wider exposure. Lex Scott Davis, also recently impressive in SuperFly, provides a forceful, frustrated presence as Nya, a community organizer protesting the plan. Meanwhile, Joivan Wade conveys confusion and compassion as her brother, Isaiah, as he weighs his options against Skeletor (a truly terrifying Rotimi Paul), a neighborhood psycho for whom the Purge is a buffet line of bad deeds.

As official Purge participants, Isaiah and Skeletor are among those wearing contacts meant to record their activities for analysis but that mostly serve to make their eyes glow like a “Thriller” video. Goofy, but more acceptable than the fourth go-round of clumsily overcomplicated murder cosplay common to every Purge movie and laughably justified here as some emblem of the shame people feel in carrying out these acts. Here, two women rig stuffed animals to explode as they blare the Dazz Band’s “Let it Whip.” There’s also a subterranean would-be rapist strapping a decapitated baby doll’s crying voice box to his face in order to lure women.

Prior to the Purge, Isaiah has taken to selling drugs for Dmitri (Y’lan Noel of HBO’s Insecure), known as the “Big Dog of Park Hill.” Nya doesn’t know it and neither does Dmitri, but this revelation throws these former lovers back together as eventual allies. The drug-dealer redemption arc is tired, but Noel gives it so much young-Snipes swagger and gravity that it’s impossible to walk away feeling like he won’t be a star by the time a seventh Purge is here.

Discouraged by relatively low turnout, the NFFA sends in goon squads to goose the results as Tomei poorly feigns fury over the fouling of her data. It’s the same revelation as later Purge films, but a feeling of “rigged from the start” lends an urgent, aggressive and unmistakably topical slant.

There’s an undeniable kick to watching people of color disarm, dismantle and / or disembowel dickheads in Klan robes, and McMurray sure films it like a house on fire. However, DeMonaco makes a conscious choice about those (and other) characters’ motivation that dismisses their deeds as performative smokescreen rather than racism’s pervasive rot. In doing so, DeMonaco avoids any meaningful, meaty engagement with the real terrors The First Purge tries to rile up. It leads to an abrupt, anticlimactic end and a Kendrick Lamar song stinger it just does not earn.

A mostly moribund misfire, The First Purge perhaps reveals its true purpose in superfluous shots of a poster for producer Jason Blum’s forthcoming Halloween remake on Isaiah’s wall … or interrupting the end credits with a teaser for an upcoming 10-episode Purge TV series set somewhere along the timeline. Maybe that outing will return to exploring how our analogous anxieties have continued to evolve, but The First Purge disappointingly settles for pure economic expedience.