It is uproariously entertaining to see the scurryings of the innumerable host of Democratic presidential candidates in what is already more of a lottery than a quest for the world’s greatest office.

It’s a stampede to (and over) the edge of the abyss of all who advocate open borders, 70 percent income taxes, the green terror, socialized medicine, legalized infanticide, reparations to Native and African-Americans, packing the Supreme Court and abolition of the Electoral College.

The charge to oblivion reminds me of 1972. That year, Sen. George McGovern was nominated on a platform that included a general income tax increase, the transportation by school buses of millions of children all around every metropolitan area to distant neighborhoods in search of “racially balanced” schools and a capitulation to North Vietnam.

As Nixon recounted to me, when McGovern finished his nomination acceptance speech in Miami, the president turned to his wife and said: “All our time in politics, we have fought the Democrats of Roosevelt, Truman, Stevenson, Jack, Lyndon and Hubert; all substantial and formidable men. How did that great party fall into the hands of such jerks?”

In 1972, McGovern fairly defeated “Scoop” Jackson, Edmund Muskie, Hubert Humphrey and George Wallace for the Democratic nomination. All of them except Wallace were moderates and would have put up a reasonable alternative to Nixon. But McGovern’s electoral death wish gave Nixon what remains the greatest plurality in American history — 18 million votes — though the electorate has grown by almost 80 percent in the intervening 47 years.

Today’s Democrats are retracing McGovern’s path in 1972, and it’s almost too late for any of them to shift lanes into plausible electability. Two of the four who might have done it — Mike Bloomberg and Sherrod Brown — have pulled out. Sen. Amy Klobuchar of Minnesota has kept her head screwed on in policy terms but shows no sign of stirring the voters.

The last and not the best hope of sane Democratic contenders is that very tired old plough-horse Joe Biden. With all his malapropisms and foolish ideas, Biden is at least not a terrifying radical. And now he is being sandbagged because he allegedly touched two or more women many years ago, perfectly legally, with no discreditable intent, out of affection with no claimed sexual aspect. It is to this unimaginable depth of idiocy that the American Left has descended.

Biden is a memorably unprepossessing candidate for the headship of the American government. Putting tired, banal, stale, but oddly equable old Joe up against the rampaging lion who is the incumbent would be like sending Frederick the Mouse of the children’s bedtime stories to do battle with my late Siamese wondercat, Sidney.

Despite Biden’s regret that he never had the opportunity at school to take Trump “behind the gym and beat the hell out of him,” any such match, politically, would be like Sonny Liston’s bout with Albert Westphal: four steps of pursuit, a one-punch knockout and, as Liston said: “I didn’t sweat, so I don’t even need a shower.”

South Bend, Ind., Mayor Pete Buttigieg has to a slight extent avoided the minefield of policy disaster areas. Of the lethal landmines upon which most of the Democratic candidates are now stamping their feet, he only seems to subscribe to the climate change fantasy and socialized medicine, though he is also an enthusiast of the putrid corpse of organized labor.

Even so, America isn’t going to elevate to the White House a 37-year-old gay mayor of a city of 102,000 people, the pinnacle of whose political career was retiring from a run for chairman of the Democratic National Committee on the day of the election. At least Beto O’Rourke, halfwit though he is, gave it a great try for the US Senate from Texas.

The Democrats temporarily have become a hopeless party. As the Russian-collusion fraud vanished, so did any possible argument that there isn’t really a crisis on the southern border. The Trump tax and deregulation reform maintains a full-employment, noninflationary economy with rising wages and family purchasing power and a growing workforce.

The Democrats haven’t got the message, but those who aren’t punch drunk out of their senses will decode the political message the night of the election in November 2020. Then, when they have dug out from under the rubble of their fantasies, they can start to rebuild.

Conrad Black’s latest book is “Donald J. Trump: A President Like No Other.” This column was adapted from American Greatness.