I'll try not to give away anything important about the ending, however this review has some potential spoilers about The Purge. Ironically, it serves the cathartic urge to see people heroically defending their families -- but in spite of the film's premise, don't expect the national crime rate to magically drop.
On the surface of things, The Purge seems a little hard to peg in terms of its philosophy. When the security system fails, as you know it will, the family must rely on guns and the good ol' 2nd Amendment to protect themselves. There was at least one pro-military nod in it as well.
The basic premise of the film, also presented in the official trailer, is that America has solved almost all its domestic policy problems. Crime is extremely low and unemployment is down to a ludicrous 1%!!!! Wow. Unfortunately, the lynchpin of this new American society seems to be a national holiday in which America takes a total break from law and order. No law enforcement and no emergency services from dusk till dawn on Purge Night. High government officials are exempt from this glorious tradition, kind o' like our Congress wants to be exempt from the Affordable Care Act.
I don't know if I'll spend much time on the plausibility of this premise here, but it is implied that most crime stems from people's resentments and that this is mostly solved by giving them a single night each year to, as Fox Mulder would say, get their "ya-yas" out.
So why would liberal Hollywood make a movie about a family needing to protect itself from home invasion with guns. Well, first of all, it's implied that the only reason any guns are necessary is that the police are not available during Purge Night. Yes, otherwise, the police would always arrive in time to prevent the crime instead of clean up after the crime.
Next, Purge Night is wrapped in patriotic fervor. The new American government sends messages to the public about Purge Night that are wrapped in God and country, very explicitly so. This was all set up by the "Second Founding Fathers." Yes, this second set of Fathers have re-Constituted America, and their God-and-country formulation has them make the public dependent on a national system of emergency services (that CNN maligned Romney for insufficiently supporting) that can be suspended on a national level. And this is done, so the movie implies, to weed out the poor and inconvenient, just as the recent, even less plausible sci-fi In Time has also troped.
To drive the class warfare theme home, the initial and principal victim of Purge Night in the film is a poor, black man, and the main villain is an ultra-Nordic, ultra-blond rich kid complete with prep school uniform who looks like he should also be in a skeleton costume chasing the Karate Kid around the school [shameless Social Network reference]. Yes, he is the missing evil triplet from the Winklevi litter. So bored with his privileged (and religiously patriotic) life that he looks forward all year to hunting down a poor black man.
In this film, terror will visit the home of the protagonist family so as to atone for them making money off of Purge Night by selling security systems, which would presumably also not be necessary if it weren't for Purge Night. Even the other rich people in the rich neighborhood despise these people for making money this way. He's obviously concerned about his neighbors, but the fact that he makes a lot of money off of these expensive systems makes him a bad guy. The movie glides right by the obvious notion that one would not need to believe in the rightness of Purge Night, as Ethan Hawke's character does, to feel good about providing an important service to people. In fact, the movie tries to impugn him for not making these systems 100% villain-proof, just as car companies are often maligned by liberals for being unable to provide a 100% safe care.
To me, this seems like a thinly veiled reference to the firearm industry. Like Michael Moore's self-congratulatory agitpropumentary Bowling For Columbine which incriminates a store for selling bullets and thus profiting from human misery, the film producers seem to incriminate people for actually making a profit from providing a necessary or useful service. So evil. No, he should be campaigning against the totalitarian regime (how should he do this exactly?) that prevents state and municipal authorities from providing vital protections to their people, instead of providing security services. How 'bout these security details that rich liberal Hollywood celebrities buy for their children while campaigning against our 2nd Amendment rights? Shouldn't these evil corporations be providing us regular people their services at affordable prices instead of catering to celebrities?
One thing that the film almost gets right is that the main character explains that no system is 100%. What he doesn't explain further is that everything is a tradeoff. 90% safe is more expensive than 85%. 95% is twice as expensive, and 99% is 5 times as expensive. The most affordable protection is a gun. Many Americans that claim to be poor sport iPhones and smart phones. If you can afford these phones you can afford a gun. And the film is correct when the guns end up being worth a lot more than the very expensive security system.
Back to the film's sense of moral outrage: In the film, it is the youth of America that are the voice of conscience. The "Question Authority" generation knows right from wrong and generously puts the whole family in jeopardy to feel better about being rich and safe. You see, there was a moral obligation to let in a stranger who claimed to need help. No chance that this could have been a ruse on a night where murder, rape, and torture become completely legal (as long as the firearms used are not those outlawed by the totalitarian regime). And no obligation to keep one's family safe. The family is completely in harm's way because of the "selfless" actions of the youth who are willing to sacrifice the family for the right cause. Now, I'm not ridiculing the sentiments--they are very natural--but sentiments do not change reality, and that's why the young are not more circumspect than the adults. What the film unintentionally gets right is that youth are the most easily manipulated segment of society.
We are supposed to despise the moral weakness of this father for being willing to save his family at the expense of a total stranger, and yet, in the movie Olympus Has Fallen we are supposed to feel sympathy for a President who just might sacrifice the safety of the whole nation to save his son and who will sacrifice the safety of the nation just to save his Secretary of Defense. After all, the President is only human. On the other hand, this father in The Purge is a filthy capitalist swine.
So what are we to make of a film that alleges that God-fearing patriots will supplant our Constitutional government with a more heavily nationalized system that suspends government protections at will and apparently suspends common law and notions of malum in se along with the rest of law and order? If you are conservative and/or libertarian, you may not know whether to shake your head sadly or to burst out laughing uncontrollably after watching liberals furious with "Bush the Constitution-Shredder" be absolutely fine with Obama's "ad hoc legal regimes." After the last four years of God-fearing patriots being ridiculed for their misplaced fervor for the ultimate "restraining order against tyranny." After many more years of 9th Amendment rights (yes, this is also in the Bill of Rights) being libeled as racism and despotism and theocracy. (All barriers to centralized power must be destroyed in the name of liberty! Who says progressives didn't learn anything from Herr Fuhrer?)
After decades upon decades of Progressives seeking more centralized, more nationalized services, seeking to put the public at the mercy of public services with collective bargaining power to perpetually extort the public for a better deal. After the Progressives praised Hitler for his more centralized, more nationalized programs that arbitrarily decided to put undesirables on the path to either forced sterility or euthanasia, (before the scandal of genocide changed the political climate)? After decades of Progressives defending socialists' totalitarian oligarchies for letting their people starve by the millions, sacrificing large numbers that their system couldn't support (because protecting their people from the evils of voluntary business transactions was much more important). Google libertarian Dan Mitchell's many posts on the national healthcare in the UK and how financial pressure have put various babies and elderly onto the death pathway.
No, we've learned these last three years that the only time progressives are worried about government having too much power is when a supposed conservative is at the helm. Otherwise don't be worried about government intrusion. Don't listen to those voices warning of tyranny lurking around the corner. Only be fearful of those dangerous conservative nuts who given half a chance would make our unemployment rates drop using a national murder holiday. Such a horrific idea would never come from the Left; collectivists have never after all been pragmatic about the value of human life. Let's hope Progressives never get the idea that "aborting" kids up to one year after birth would reduce unemployment, because if it could get us down to even 4%, there would be a national celebration of killing that would coincide with the Democratic National Convention. Actually, maybe we already have that.