A North Carolina man walks into a popular Washington D.C. pizzeria and opens fire, telling police upon his inevitable arrest that he came to "self-investigate" a widely debunked conspiracy theory involving former Democratic presidential candidate Hillary Clinton.

Tom Nichols (The Federalist)

In Hollywood, actress and model Jenny McCarthy and others wage a campaign against mandatory vaccinations for children, despite mountains of evidence showing they're the key to preventing debilitating childhood diseases.

At the dinner table, your loudmouthed uncle holds forth on the events of the day, insisting he's right and refusing to accept counter-arguments, even as he mangles facts and disregards clear truths.

Separately, these are amusing - and maybe a little disturbing, anecdotes.

But taken together, they're part of "the death of expertise," a stubborn insistence by the ignoramuses in our midst that everyone is as smart as everyone else; that expert opinion is meaningless and that any attempt to dismiss such claims is just "elitism."

Tom Nichols, a former staffer to the late Pennsylvania U.S. Sen. John Heinz, and a professor of national security affairs at the U.S. Naval War College in Newport, R.I., stirred the pot of debate this summer with his new book, sensibly titled, "The Death of Expertise: The campaign against established knowledge and why it matters."

The slender, green-and-white tome weighs in at just 240 pages, but it makes a powerful and compelling argument.

Namely, that despite having access to more information than ever before, Americans are not only getting dumber, they're also proud of their ignorance and can't be moved off their opinions - no matter how effective the counter-argument with which they're presented.

If you've ever spent time hanging out in the comments section, well, you know exactly what Nichols is talking about here.

But the consequences of this intransigence are pretty clear.

And it goes beyond gun-wielding yahoos who take it upon themselves to investigate conspiracy theories so ridiculous - that Clinton was allegedly running a child-sex ring out of a D.C. pizza joint - that most sensible people dismiss them out of hand.

It's the impact that this kind of willful ignorance has on our public dialogue, in a refusal to agree to commonly accepted norms of knowledge: Inevitably, it will lead to a decay in our politics and erode our democratic institutions.

"The bigger problem is we're proud of not knowing things," Nichols writes. "Americans have reached a point where ignorance, especially of any public policy issue, is an actual virtue."

He lays blame for this phenomenon in a couple of places.

Among them, the fever swamp of the Internet where "confirmation bias" reigns supreme; the galaxy of "news" sources that exist to reaffirm and stoke those prejudices; and on college and university campuses, where students become "clients" to be coddled rather than challenged.

Of course, there's always been a strain of "know-nothingism," in our politics. And there's a good reason why characters like Cliff Clavin, the blowhard mailman on the old sitcom "Cheers" was so popular - everyone knew someone like that.

The difference now, Nichols argues pretty convincingly, is that when they were presented with facts proving them wrong, the Cliff Clavins among us used to back down.

These days, your drunk Uncle Harry dismisses contradictory evidence as "fake news" and "alternative facts" and goes blithely on his way, leaving a gaseous trail of toxic misinformation in his wake.

But it's not "that people don't trust experts or eggheads," Nichols said in an interview.

Nope, it's worse than that: "It's that they have actually come to believe that they're smarter than those experts."

"Increasingly, laypeople challenge experts by trying to explain their own subject back to them," he continued. "'Oh, you're an expert on Russia? Well, let me explain Russia back to you.' This is not skepticism, it is narcissism."

And in case you're inclined to dismiss that argument out of hand, think for a moment how many times you've self-diagnosed a malady on WebMD and then quibbled with your family doctor over what actually ails you.

That's the kind of narcissism that Nichols describes.

And to that end, a little education can be dangerous. In fact, Nichols observes, there's something to the argument that college isn't for everyone - even if we've been telling our kids the opposite for years.

Many of today's students, who have been ushered down the road to higher education without preparation or the skills to handle it "are less able to distinguish fact from opinion, to engage in analysis or to reach difficult conclusions," Nichols said. "They are often just passive recipients of information of varying quality, delivered through electronic means as just so many data points or pictures."

The result, he says is that "college attendance is no longer a guarantee that people know what they're talking about."

To his credit, Nichols doesn't look away from the fact that sometimes the experts get it wrong.

Take, for instance, the eighth-grader who shot down a respected scholar's widely accepted argument that the "No Irish Need Apply" signs in the late 19th century were myths.

The 2015 story of the student, Rebecca Fried, and the expert, University of Illinois professor Richard Jensen seemed to "encapsulate the death of expertise," Nichols writes.

The "death of expertise" trend reached its absolute apogee in 2016 when billionaire Donald Trump, who merched the debunked "birther" conspiracy involving President Barack Obama, won the White House.

Trump, who has been caught in seemingly countless fibs and fabrications since, screams "fake news" at the slightest criticism.

And he routinely undercuts the credibility of government institutions, as in the case of his ongoing fight with the intelligence community over Russian meddling in the 2016 election.

Trump's bleating about "fake news" is dangerous because "it makes news the vessel for partisan politics rather than a presentation of ideas or facts. We now distrust the politicians, and the sources that check on the politicians," Nichols says.

So where does that leave us? Are we just doomed to get dumber and dumber until the flow chart of human intelligence looks like the "Ascent of Man" drawn in reverse?

Unfortunately, according to Nichols, the answer is "Probably, yeah" (and I'm paraphrasing here).

"My concern is that this won't end until a populist fad like anti-vaccines cause a disaster. Diplomacy will come back as a skill when we face war -- or are in one," he said. "We might start consulting economists during the next depression. Populism always drives itself into the ditch, and experts always have to fix it. It's one of the reasons people resent experts; we're the people who generally have to repair the damage on the morning after."

Note to self: Stock up on both canned goods and economists in the event of the apocalypse.