The central assumption of democracy — beyond the assumption of fair elections, which is disturbingly questionable — is that voters are the possessors of their own “interests,” and vote for the candidate most sympathetic to them.

But of course those interests are fair game for advertising, bombast and propaganda — and the psychology of fear.

Thus, not only are candidates capable of misrepresenting their support of people’s interests, even more insidiously, they engage baldly in manipulating them. This is a game that turns the endless presidential campaign season, especially as it is conveyed to us in the mainstream media, into little more than a mish-mash of clashing sound bites: full of sound and fury, you might say, but signifying nothing, or at least nothing much.

The two-party system, which comes to us courtesy of Big Money and is taken so seriously by the media — as seriously as any advertising campaign takes itself — is, essentially, a race to seize control over the nation’s collective reptile brain.

Let’s make America great again!

Welcome to the 2016 presidential campaign, underway well over a year ahead of time and already devolving into cartoonish absurdity, thanks to the loudmouth billionaire who leads the Republican fray.

Donald Trump, with the help of his money and his ego, is exposing the absurdity of American politics like no one else I can remember. Whoosh! Gone is the protective veil of political correctness. Let’s hear it for naked cynicism!

“When Mexico sends its people, they’re not sending their best. They’re not sending you. They’re not sending you. They’re sending people that have lots of problems, and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.”

As far as I can tell, Trump is the unapologetic standard bearer of late-stage, theater-of-the-absurd American exceptionalism. He directly addresses the prerequisite for national identity: an enemy. Someone to hate. Someone to fear. This is nationalism; this is Republicanism. And Trump brings his own special twist to it: a gleeful American inclusiveness.

And not a moment too soon, here in “post-racial” America. As Rick Perlstein astutely pointed out last month, Trump’s inflammatory, anti-Mexican, anti-immigrant announcement of the start of his presidential campaign — presenting a gift-wrapped enemy to the racist that secretly lurks in so many American hearts — was almost precisely juxtaposed with the immensely symbolic lowering of the Confederate flag in South Carolina. “And, immediately, Trump shot to the top of the Republican charts — with a bullet,” Perlstein wrote.

He added: “I’ve never seen anything that lays bare the core lineaments of conservatism so neatly: There is our tribe, which is good, true, and pure; and there are those other tribes, who are existential threats to you and me (Reagan’s favorite phrase), and must be suppressed in order for good to be preserved. ‘We’ all know this, even if ‘they’ don’t allow us to say this. If anything, the lowering of the Confederate flag in South Carolina opens space for this particular new longing to air this other silent truth more freely.

“This is important: Conservatism is like bigotry whack-a-mole.”

But there’s a special brilliance to the reconfigured racism Trump is offering to the American people.

Consider this paragraph from Trump’s campaign website. When you click on “positions,” only one topic shows up: immigration reform. And it’s not just any old immigration reform, it’s IMMIGRATION REFORM THAT WILL MAKE AMERICA GREAT AGAIN.

As the website explains: “For many years, Mexico’s leaders have been taking advantage of the United States by using illegal immigration to export the crime and poverty in their own country (as well as in other Latin American countries). They have even published pamphlets on how to illegally immigrate to the United States. The costs for the United States have been extraordinary: U.S. taxpayers have been asked to pick up hundreds of billions in healthcare costs, housing costs, education costs, welfare costs, etc. . . . The effects on jobseekers have also been disastrous, and black Americans have been particularly harmed.”

There are several reptile-brain subtleties of note here. First of all, the illegal immigration flow, according to Trump, begins with the machinations of “Mexico’s leaders.” It’s not a poverty-induced bleeding of the poor across the U.S. border but a deliberate, provocative act by one nation against another: something like an invasion. The Donald is not only giving us a subgroup to hate. He’s giving us war!

Perhaps even more appallingly, Trump makes a point of saying that “black Americans have been particularly harmed” by this invasion. Thus he opens the door to Black America to join the “We Hate Mexicans” club, in effect, creating a more inclusive form of American racism — the benefits of which, of course, will be reaped by his campaign.

Perhaps what this is really about is the slow-motion collapse-into-absurdity of the American empire, as Trump makes the emotional glue of hate and fear that has held it together for two and a half centuries unbearably obvious. The question he inspires, which lurks just beyond the horizon, is what sort of political entity we can build that isn’t based on these shadow “interests.” What happens after we stop seeing ourselves as conquerors? Can we build a country that honors, and fits into, a global whole?