Earlier this month, a video of Joe Biden saying he had “no empathy” for “the younger generation” that “tells me how tough things are” resurfaced on social media. The video was over a year old, but it elicited predictable howls from members of the dissed demographic. “Nothing says ‘perfect candidate to lead the most powerful nation in the world’ like ‘I have no empathy,’” wrote someone with the Twitter handle @anarchopriapism.

My own reactionary reaction was different. O.K., I thought, I could definitely vote for Joe — provided he has the mettle to stand his ground.

I’ve been saying for a while now that both parties could use a Sister Souljah moment, in which a candidate shows the intestinal fortitude to rebuke some obnoxious person or faction within his political base.

Bill Clinton did it in 1992 after the recording artist Lisa Williamson asked, “If black people kill black people every day, why not have a week and kill white people?”

Clinton called it out as an example of reverse racism and still went on to win 83 percent of the African-American vote.

In this election cycle, no faction on the Democratic side more richly deserves rebuking than the one Biden singled out — which is not, of course, anywhere close to the entire millennial generation (roughly 80 million strong), or their younger siblings in Gen Z.

But it is that part of these younger generations that specializes in histrionic self-pity and moral self-righteousness, usually communicated via social media with maximum snark.

Gawker spawn and HuffPo twerps: This especially means you.

It also means all those who recklessly participate in the search-and-destroy missions of the call-out culture.

These are the Harvard students who demanded, and last week obtained, the dismissal of law professor Ronald Sullivan and his wife Stephanie Robinson as faculty deans at an undergrad dorm because Sullivan had the temerity to join Harvey Weinstein’s defense team.

They are the Middlebury students who in 2017 violently assaulted professor Allison Stanger for the crime of moderating a talk with Charles Murray.

They are the Yale students who in 2015 surrounded and hounded professor Nicholas Christakis because he would not agree to their demands that he denounce his wife for believing in free speech.

The signature move in each of these instances (and there are so many more) is to allege an invisible harm in order to inflict an actual one.

In place of an eye for an eye, we have professional destruction for emotional upset. Careers and reputations built over decades come to ruin, or nearly so, on account of a personal mistake or a disfavored opinion.

All of these struggle sessions play to the sound of chortling twenty-somethings, who have figured out that, in today’s culture, the quickest way to acquire and exercise power is to take offense.

This is easy to do, because the list of sins to which one may take offense grows with each passing year, from the culturally appropriated sombrero to the traditionally gendered pronoun.

It’s also easy because the grown-ups rarely push back and, in fact, are often happy to go along.

Not one of the students who joined the mob at Middlebury was expelled.

And say what you will of the students who demanded the ouster of Sullivan and Robinson, they would have gotten nowhere without the weaselly connivance of Harvard Dean Rakesh Khurana, who discovered unspecified problems with the “climate” of the dorm in order to justify his verdict.

Which brings me back to Biden.

The rap against the former veep is that he’s old, frequently puts his foot in his mouth, and occasionally says nice things about Republicans.

Another way of putting all that is that he’s mature, unstudied, and not just another partisan hater.

Also, he refused to beg forgiveness last month for being a tad too touchy-kissy.

Maybe he should keep his hands in his pockets, but at least it means he isn’t prepared to capitulate to the icy codes of personal decorum written by people who don’t know the difference between exuberant human warmth and unwarranted sexual advances.

To which one can only say: Keep it up, Joe!

He’s already leading all of his Democratic primary rivals in every demographic group save millennials (obviously), where Bernie Sanders has a narrow lead.

He could make a virtue of the defect by emphasizing his distance from everything that defines the worst aspects of millennial culture — the coddled minds and censorious manner and inability to understand the way the world works.

Does it ever occur to some of our more militant millennials that the pitiless standards they apply to others will someday be applied pitilessly to them?

The sensible center of America — that is, the people who choose presidents in this country — wants to see Donald Trump lose next year, but not if it means empowering the junior totalitarians of the left.

Now is Biden’s chance to make it clear he’s just the man to fulfill that hope.

— Bret L. Stephens has been an Opinion columnist with The New York Times since April 2017.