Viscerally effective but intellectually indefensible, the third installment of James DeMonaco’s horror franchise makes the leap from sheer mindless violence to simple-minded (but still gory) political thriller, managing to get even scummier in the process. By adding jejune socio-economic commentary to the mix, “The Purge: Election Year” pretends to be making a point about inequality in America while still just appealing to the audience’s vicarious bloodlust.

The fundamental premise of the previous pictures remains: under the aegis of a shadowy group called the “New Founding Fathers,” the United States practices an annual event, a twelve-hour period when anyone is free to allow his id to run rampant and engage in murder and mayhem, with no legal ramifications. The purpose of the exercise is justified as a means of exorcizing the base instincts of the community, but it’s become obvious to a growing proportion of the citizenry that the real purpose is to weed out the chaff of the population and enable the oligarchs to retain their power and wealth without having to support a worthless underclass. If a little blood is spilled in the process, that’s a price they’re willing to pay—or more properly, have others pay.

The status quo is threatened, however, when Senator Charlie Roan (Elizabeth Mitchell), who—as a prologue graphically demonstrates, lost her family as a teen, victims of a Purge Night crazie—runs for the presidency on a pledge to end the annual ritual by executive order. That prompts the evil cartel (headed by veteran character actor Raymond J. Barry, unleashing his best sneer), to plan Roan’s death as one of the Purge’s victims. She’s being protected by Leo (Frank Grillo), the hero of the previous installment who’s now the head of her security detail; but others in her entourage betray them, and soon they’re on the run, pursued by the team of special forces goons led by nasty Earl Danzinger (Terry Serpico).

Fortunately they soon get allies. Two are Joe Dixon (Mykelti Williamson), the gruff but principled owner of a deli who’s defending his place against a passel of bloodthirsty schoolgirls led by a nasty piece of work called Kimmy (Brittany Mirabile)—just after he’s lost his “purge insurance,” no less—and his faithful clerk Marcos (Joseph Julian Soria), a Mexican-American who believes in Roan’s candidacy. Another is Laney (Betty Gabriel), an erstwhile gang member who now patrols the streets of Purge Night in an armored truck to help injured victims. And a third is Dante Bishop (Edwin Hodge), the leader of anti-purge activists who aim to assassinate Roan’s opponent, a fanatical minister named Owens (Kyle Secor), during the so-called “Purge Mass” he annually holds in his cathedral before an enthusiastic audience of bigwigs, including the Founders.

It’s the church where the plot culminates, but only after a succession of chases, close calls, gunfights and hair’s-breadth escapes, periodically interrupted by gratuitous episodes of killing and menace. (One of the more grotesque inventions of the script is the arrival of “Purge Tourists,” who come from other countries to satisfy their need for bloodletting. We’re introduced to group from Russia, and satisfied when they’re unceremoniously mowed down while threatening Roan and Leo.) During all the nocturnal meandering the senator is captured and prepared for execution in a perverted ritual of purification at Owens’ mass, and Leo and his new friends must save her—naturally in a hail of bullets.

Under DeMonico’s increasingly sure hand “Election Day” proceeds with relentless efficiency, manufacturing audience outrage while simultaneously satiating their desire for mayhem. The physical production is basic but appropriately moody, though Jacques Jouffret’s cinematography does exhibit a proclivity for hand-held messiness in the action sequence. The acting hardly gets beyond the pedestrian, but Grillo makes a properly impassive hero while Williamson garners the lion’s share of the laughs and Soria stands in for all the Mexican immigrants trying to make an honest living in the States (take that, Trump!). Mitchell puts on a game show, but never really convinces as a political powerhouse. Particular note may be made of Secor, who goes bonkers with such zest you might genuinely fear for his sanity.

This isn’t the first time that the horror genre has been used to advance the idea that the rich are preying on the poor—Brian Yuzna’s little-seen 1989 “Society” actually portrayed the well-to-do as monsters literally feasting on the flesh of ordinary folk. But this latest entry in the “Purge” franchise touches a nerve, appearing at time when the political climate in this country has grown so heated. The character of Marcos tells you a good deal about where it stands, but one need only look at the electoral map glimpsed briefly at the close to see its point of view even more clearly.

Of course, whether viewers who plunk down money to lap up the gruesomeness the picture provides will embrace—or even perceive—the message is debatable. In fact, they might line up with the demonstrators we hear about at the close protesting the possible end of Purge Night—a group that will undoubtedly become more active in the sequel that will undoubtedly follow in a year or so if “Election Day” proves a box office winner.