As George Santayana wrote, "Those who cannot remember the past are condemned to repeat it."
While it is unfair to ask the new leftists of today to recall the events of 1972 (that happened 17 years before Alexandria Ocasio-Cortez was born), they would do well to study its history.
Because they may be reliving it.
The election of Richard Nixon and defeat of Democratic candidate Hubert H. Humphrey in 1968 was a seminal moment in our history. The left's hatred of Nixon was then as great as it is of Donald Trump today, but of longer vintage. The liberals had been anti-Nixon ever since he began his career in 1946.
Humphrey was the Hillary Clinton of his day. A perennial candidate, he was the presumptive Democratic nominee.
Everyone assumed it was his turn to run for president after serving as Lyndon Baines Johnson's vice president.
But he faced an unexpectedly strong challenge to his nomination (some said coronation) from Sens. Eugene McCarthy and Robert Kennedy, just as Hillary had to fend off Bernie Sanders.
After Humphrey went down to defeat at the hands of Nixon, the left felt it would continue its march to take over the Democratic Party, just as it did after Hillary's loss. In both cases, they moved the party to the left, capitalizing on the disappointment in the Democratic establishment and the hatred of the GOP incumbent.
The liberal media cheered the left on then as now, according massive coverage to its icons (Abbie Hoffman and Jerry Rubin then and Alexandria Ocasio-Cortez and the new Muslim congresswomen from Michigan and Minnesota, Rashida Tlaib and Ilhan Omar, now).
In 1972, Sen. George McGovern of South Dakota emerged as the champion of the left, vanquishing Humphrey in the presidential primaries of 1972.
Likewise, now a crowded field of leftist Democrats are emerging as contenders for their party's nomination, moving demonstrably to the left of Joe Biden, the establishment's mainstay.
And then, as now, the media cheers them on, breathlessly predicting their ultimate victory and celebrating their wins along the way. The momentum of the left seemed unstoppable in both years.
Until it was stopped, massively and completely in 1972 by the Nixon re-election campaign. Their progress, celebrated by the media, came to a crashing halt amid one of the greatest landslides in electoral history.
Nixon won 49 states, leaving McGovern with only Massachusetts and D.C. Nixon won 61 percent of the popular vote.
Under the protective coverage of the liberal media, the 1972 radicals had moved so far to the left that they abandoned their party's traditional base. In the liberal echo chamber of the sycophantic media and the cheering campuses, they had deceived themselves into believing that the country was on their side.
But the reality check of Election Day was brutal.
(The left's reversals were short-lived because Nixon's Watergate scandal and resignation erased the memory, but then-moderate Jimmy Carter still beat the leftists for the Democratic nomination in 1976).
Today, we see the left in the process of the same sort of self-immolation, embracing schemes for "Medicare-for-all," open borders, legalized drugs, free tuition, a $15 minimum wage and a green agenda that calls for an end to air travel.
So many Americans do not like Donald Trump (I do), just as so many did not approve of Richard Nixon. But just as Nixon's negatives were overshadowed by fear of the leftist McGovern, so those of Trump may be overcome by revulsion against the new socialist Democratic left.