It may be about time to add a new chapter to Charles Mackay’s Extraordinary Popular Delusions and the Madness of Crowds. Mackey dilated on scams like the South Sea Bubble and wild speculations like Tulipmania in 17th century Holland, when a single tulip bulb could sell for more than a mansion.

There was the distinct aroma of fraudulence, abetted by naïveté, about most of the enterprises Mackay described. And so it is with the new chapter I am proposing. It might be called “Russian Roulette.” I am thinking not of the messy game with a revolver, but rather the insinuation sweepstakes currently being deployed against Donald Trump by the Democrats and their pets in the media.

Since the game is still in process, we cannot quite finish the chapter. But we know how it starts. It starts with groundless accusations that Donald Trump and/or his surrogates somehow “colluded,” had illicit ties with, the Russians. Maybe he helped them “hack the election.” Maybe he is Putin’s puppet. We don’t quite know. But this calls for a “special prosecutor” (even though such a thing doesn’t exist), a criminal investigation, the impeachment or at least the delegitimization of Donald Trump and all his works.

Last week, Holman Jenkins had an excellent, sobering-up piece on the Left’s “Putin Fantasies.” He quickly dispatches all the usual suspects: Paul Manafort, Roger Cohen, Carter Page, et al. He quotes “veteran foreign correspondent Susan B. Glasser,” who treats readers of the New York Times to this breathless animadversion:

Mr. Trump’s rhetoric and actions as president bear more than a passing resemblance to those of Mr. Putin during his first years consolidating power. The similarities are striking enough that they should not be easily dismissed.

Oh, yes: “The similarities are indeed striking,” Jenkins observes. “Mr. Putin and Mr. Trump both have arms and legs. When it comes to distinguishing noise from signal, however, two men could not be less alike”:

Russia was a country in chaos. Its president was a drunk seeking a successor to protect his daughter and friends from corruption investigations. Mr. Putin, a former KGB agent and head of the secret police, ran one of the few, after a fashion, functioning institutions in Russia, albeit arm in arm with organized crime. Mr. Trump’s rise couldn’t be more different. He’s a reality TV star and brand manager. To an unusual degree, he’s a president who lacks even a party. Meanwhile, the courts, the bureaucracy, the media, the political parties all continue to function as they always have.

“Striking similarities” underwritten by categorical differences.

No, when it comes to this new game of Russian Roulette, Ted Cruz got it right: it is a “nothingburger.”

Well, not quite nothing. So far, there is no evidence of malfeasance, of anything improper or illegal. But there is plenty of anchorless animus directed at Trump by the Democrats and their media pets. So far, it amounts to what William Jacobson at Legal Insurrection has called “The fact-free Intelligence Community-Media trial of Trump by innuendo.”

Here’s how it works. You start with a lurid — but totally unsubstantiated — allegation. To wit: Senator Chris Coons (D., natch) to Dem. pet Andrea Mitchell March 3:

There are transcripts that provide very helpful, very critical insight into whether or not Russian intelligence and Senior Russian leaders, including Vladimir Putin, um, were cooperating, were colluding, with the Trump campaign at the highest levels to influence our election.

Yikes! Transcripts and evidence of collusion at the highest levels to influence our election. Andrea Mitchell sure liked that:

Holy smokes!

Actually, it’s holy smoke and mirrors.

On March 3 it was “transcripts,” Russians “colluding” with the Trump campaign “at the highest levels to influence our election.” But by March 5 it was “I have no hard evidence of collusion.”

No “hard” evidence, of course, means no evidence of any kind.

I adduce the example of Chris Coons, but remarks by Nancy Pelosi, Chuck Schumer, et al. — not to mention the yapping of any of the pack of chihuahuas that is the Democratic pocket press — would do just as well.

Take a damaging allegation: the infamous “dossier” against Trump, for example. It doesn’t make any difference that it is totally unsubstantiated. Just run with it.

All Democratic outlets — CNN, MSNBC, Washington Post, New York Times — echo it. Is it untrue? Doesn’t matter. It might still have the desired effect of undermining public confidence in Trump even if it is eventually exploded.

But what if you are Donald Trump? Well, that’s different. Let’s say you make allegations that the Obama administration conducted surveillance against you in the final months and weeks of the election.

Not so fast! Where’s your proof?

Actually, there’s plenty of proof. Andy McCarthy noted a few days ago:

[T]he Obama Justice Department and the FBI sought FISA warrants against Trump insiders, and potentially against Donald Trump himself, during the last months and weeks of the presidential campaign.

Even the New York Times admitted as much, if inadvertently, in a story about various investigations in Trump’s alleged “Russia ties”:

The investigators have accelerated their efforts in recent weeks but have found no conclusive evidence of wrongdoing, the officials said. One official said intelligence reports based on some of the wiretapped communications had been provided to the White House.

Just to parse that a bit: by “no conclusive evidence” the Times means the same thing that Senator Coons meant by “no hard evidence,” i.e., no evidence at all.

And although Nancy Pelosi responded to Trump’s allegation that Trump Tower had been secretly wiretapped by saying “We don’t do that,” it turns out, as the Times acknowledges, that they do.

Holman Jenkins noted in passing that Donald Trump is “a reality TV star and brand manager.” That’s right. He’s cut from a different bolt of cloth than the Democratic (and most of the Republican) confraternity. That’s one reason they so despise him.

Another, and deeper, reason is this: If Donald Trump is successful in draining the swamp of Washington, D.C., if he can effectively take on the unions, secure our Southern border, cut wasteful regulation, neuter the EPA, substantially dismantle the administrative state, and achieve 3-4% growth, all of those swamp creatures will be out of a habitat.

In other words, Trump represents an existential threat to their way of life. Hence their angry and hysterical war against him. Mostly, it is true, their attacks are self-refuting. But make no mistake. The Left is out to cripple Trump.

As I said in this space Saturday, he needs to fight back, and hard. The Left has declared war on Donald Trump. I am glad to see that he has woken up to that fact and is responding in kind.