A Rasmussen poll late last month had Donald Trump defeating President Biden by 10 points in a putative 2024 election. If Vice President Kamala Harris were the Democratic nominee, Mr. Trump’s margin of victory would be 13 points.

Polls at such a distance from a contest are wholly artificial. The political weather can change in three days, let alone three years. Mr. Trump may not run. Mr. Biden may not run. Ms. Harris may prove less inept in the next Democratic primary campaign than she was in the last one.

But...

Former President Trump speaks at a rally in Perry, Ga., Sept. 25.

Photo: dustin chambers/Reuters

A Rasmussen poll late last month had Donald Trump defeating President Biden by 10 points in a putative 2024 election. If Vice President Kamala Harris were the Democratic nominee, Mr. Trump’s margin of victory would be 13 points.

Polls at such a distance from a contest are wholly artificial. The political weather can change in three days, let alone three years. Mr. Trump may not run. Mr. Biden may not run. Ms. Harris may prove less inept in the next Democratic primary campaign than she was in the last one.

But the poll surely captures current political sentiment. The Biden presidency is a metastasizing shambles, a real-world case study in the perils of progressive impossibilism: open borders; fiscal incontinence; naive strategic idealism; mask-wielding, mandate-waving, dissent-canceling, authoritarian collectivism. Mr. Biden is Mickey Mouse as the Sorcerer’s Apprentice in Walt Disney’s brilliant, nightmarish “Fantasia.” He’s seized the magician’s big hat and now everything he touches becomes a cascading waterfall of destruction.

But the current predicament, and the poll’s judgment on it, got me thinking: How wide would Mr. Trump’s margin next time have to be for him to be accepted as president by the elites who have regarded it as their republican duty to thwart him? Ten percentage points? Twenty?

Then it was obvious. There is no margin of victory that Mr. Trump could secure that would legitimize his presidency in the eyes of the Democratic Party, the liberal media, most of the permanent government, and the rest of the establishment.

This is the larger, existential constitutional crisis the U.S. faces. It is not, as the Never Trump Robert Kagan argues in a much-discussed recent essay, all the product of a personality cult, the work of a narcissistic caudillo who emerged out of nowhere to lead an army of putschists against a benevolent state. It is deeply rooted and bipartisan; the malignancy owes at least as much to sustained antidemocratic behavior on the left and across much of the ruling classes as it does to the actions of a bombastic former president.

Mr. Trump carries a large part of the blame, to be sure. Whatever genuine doubts were sown last year by an election administered in the most permissive—and Democrat-friendly—way possible, he didn’t make a case to throw out even one precinct’s worth of votes. His continuing refusal to accept the results exerts a destabilizing force on the creaky institutions of republican government.

But it’s willful obscurantism on the part of his opponents to pretend that the threat begins and ends there. The Never Trumpers say Mr. Trump’s 2024 legitimacy has been fatally undermined by his behavior since last November. But if they were honest, the people who want to stop Donald Trump would admit that they themselves have been traducing political norms at least since he first came down that escalator in 2015. The more we learn from John Durham’s investigation about the Russia fabrications, the better we understand the scale and duration of the campaign to defeat Mr. Trump, and then, failing that, to destabilize his administration and, yes, depose him.

Were the people who conducted this campaign—inside and outside government—faithful guardians of the Constitution?

When the Russia effort sputtered, empty and exhausted, to a futile halt, these constitutional purists sought alternative ways to destroy the presidency. They seized on the killing of a black man by a police officer to unleash turmoil in the country, folding it into a narrative of racial persecution for which Mr. Trump was somehow held responsible.

“When the campaign of leaks and innuendo failed to dislodge Trump from power, the horizontally integrated pieces of the newly assembled anti-Trump messaging complex needed to pivot,” as the writer Wesley Yang puts it. “They sought a new basis for maintaining the ongoing state of emergency, and they found an out-of-the-box solution in the form of ‘anti-racist’ doctrines.”

This, in the climate of pandemic-generated fear and anger, proved a much more effective destabilization campaign. Augmented by a media and tech monolith that literally blocked news coverage unfavorable to Mr. Biden in the runup to the election, it sealed the deal.

Even then it was close. Does anyone think that if Mr. Trump had been able to flip three states that would have given him re-election, this “resistance” movement, mobilized to neutralize the “emergency” of the Trump presidency, would have accepted it?

We know the answer. We saw the proof in the days before the vote—boarded-up storefronts in major cities, a warning that, if it went the wrong way, there would be violent chaos on a scale probably larger than we saw last summer.

This narrative of continuing constitutional crisis for which only Republicans are to blame is a convenient political cover for Democrats. You will be told, even as Mickey Mouse’s reign of error continues, that you have no choice but to re-elect the people choreographing it—otherwise you will be guilty of conspiring in an overthrow of constitutional government. But until those on the other side acknowledge their own role in the undermining of democratic legitimacy, the crisis will only deepen.