This October-November 2017 marks the 100th anniversary of the launch of the Bolshevik Revolution in Russia — the bloody communist state that would produce a political-ideological killing spree unlike any the world has ever seen.

And yet, communism continues to find supporters. Here are three personal anecdotes:

I did a conference this past week on the legacies of communism. One liberal professor complained that no pro-communist speakers were included. I wasn’t surprised.

Another case: a former student of mine told me of his professor (at a local college in Pittsburgh) who was hailing Karl Marx for his “brilliance.” Again, no surprise.

One more: A student from the University of Wisconsin called in to a talk show I did last week insisting that capitalism is just as lethal as communism. That all happened just this past week, and it’s not unusual in my world.

Anecdotes aside, an October 2016 poll by the Victims of Communism Memorial Foundation generated a stunning finding: almost one-third of Millennials “believe more people were killed under George W. Bush than under Joseph Stalin.” And it isn’t only those silly Millennials. More than one in four Americans generally believe Bush was the bigger killer.

That same report found that the vast majority of Americans (75 percent) underestimate the number of people killed by communist regimes, and a large majority (68 percent) believe Hitler killed more people than Stalin.

This begs the question: How many people did these ideological gangsters kill?

Well, here at the centenary of communism, the number “100” is fitting, given that 100 million is a good stab at the number of people annihilated by the Marxist-Leninist pathology the Bolsheviks sought to spread worldwide.

The Harvard University Press classic, The Black Book of Communism, endeavored to tabulate a communist death toll in the 20th century. It came up with a figure of 100 million. The Victims of Communism Memorial Foundation also arrives at that figure. Cal-Berkeley professor Martin Malia aptly noted that the communist record offers the “most colossal case of political carnage in history.”

And even then, this frightening number — 100 million dead — is actually quite conservative.

Take the figure relating to the Soviet Union, for instance, where the Black Book recorded merely 20 million dead. Alexander Yakovlev, a high-level Soviet official who became one of Mikhail Gorbachev’s chief reformers, and who was given the post-Cold War task of trying to tally the victims, estimates that Stalin alone “annihilated … sixty to seventy million people.”

Similar levels of bloodshed was wrought by China’s Mao Tse-tung, who was responsible for the deaths of at least 60 million (according to the Black Book), but more likely over 70 million, according to the latest research. And then there were the killing fields of North Korea, Cambodia, Cuba, Ethiopia, Eastern Europe, Africa, and more.

Among these, the North Korea butcher’s bill is close to 5-6 million. And we can hope and pray that the North Korea nightmare doesn’t take on a hideous nuclear dimension under Kim. Who knows how that one could end?

Really, the death generated by communist governments in the 20th century is closer to 140 million.

By comparison, Hitler’s genocide against Jews, Gypsies, the mentally disabled, and others he deemed “misfits,” was approximately 10 million.

Finally, another chilling figure for comparison: The combined dead from World Wars I and II — the most destructive conflicts in human history — was approximately 50-60 million. One must combine and then double the tolls of the two world wars to begin approaching communism’s mass slaughter.

Ronald Reagan called communism a “disease.” Actually, it’s hard to find a 20th century disease that killed as many people as this ideological pathology. Reagan put it better when he described communism as “evil” and “a form of insanity.”

And yet, so much of this evil insanity isn’t known, nor is it being taught, especially in our universities.

A frustrated James Kirchick of the liberal Daily Beast recently asked his readers, “How many times have you heard some formulation of this viewpoint? ‘Communism is an excellent idea in theory, it just hasn’t worked in practice.’ I wish that was the sort of sentiment I only remembered from college dorm room bull sessions.”

Kirchick responded, “OK. How many more millions of people have to die before we get it right?”

Good question.

And so, as communism marks its centennial, we should remember it for what it did best: death.