A lopsided majority of Americans thought President Trump was wrong to demand funding for a border wall as a condition of ending the government shutdown. According to a CBS News poll released Wednesday, 71 percent of the public said the dispute over the wall was “not worth” keeping hundreds of thousands of government workers from getting their paychecks. Asked what Trump should do now, 66 percent of respondents wanted him to agree to a budget even if it doesn’t contain money for a wall; only 31 percent wanted him to dig in his heels.

“I am proud to shut down the government for border security,” Trump said last month in that contentious Oval Office session with Pelosi and Senate Democratic Leader Chuck Schumer. “I will take the mantle.”

But that clearly didn’t work out the way he expected. The longer the shutdown went on, the more ground Trump lost. On Friday, the president agreed to a stopgap compromise reopening the government for three weeks, allowing furloughed government employees to be paid while Congress negotiates on the terms of a budget. Yet Trump continued to insist that “we really have no choice but to build a powerful wall,” and threatened to shut the government down again on Feb. 15 if he doesn’t get his way.

By now it should be obvious that this is not a winning issue for the White House. If 71 percent of Americans resented one shutdown, even more are bound to be outraged by a second one next month. So why doesn’t Trump throw in the towel and move on to a fight he can win?

The standard response to that question is that Trump’s base would go ballistic if he abandoned his vow to put “a great, great wall” on the US-Mexico border. He made that promise on the day he announced his campaign for the White House, and has reiterated it ever since. It is the one commitment above all others — so the conventional wisdom holds — that he cannot back away from without suffering deep defections from his supporters.

Trump himself seems to believe that. “We’re going to have a wall, we’re going to have a barrier,” he said in New Orleans on Jan. 14. “I will never, ever back down.” In his remarks Friday, Trump insisted that “no border security plan can ever work without a physical barrier.”

Yet if Trump does give in, is it really so obvious that he will lose politically? I’d argue the contrary: The sooner he puts the wall controversy aside and refocuses attention on one of his other priorities — the economy, trade, judicial appointments, foreign policy — the sooner his public standing will improve. His base will not forsake him. He may have to endure a few days of grousing from agitators in conservative media, such as Rush Limbaugh, Ann Coulter, or Tucker Carlson. But their ire won’t last long. And the MAGA Nation crowds that throng to Trump’s rallies will not dwindle.

As it is, Trump has already backed away from several elements of the “great, great wall” he campaigned on so insistently in 2016.

What he once portrayed as an “impenetrable” structure made of “hardened concrete,” he now envisions as “artistically designed steel slats … that you can easily see through.” The candidate who initially boasted that he would find it “very easy” to build a 1,900-mile wall along the entire border has long since cut the projected length in half. Then there was his famous assurance that Mexico would pay for the wall. In a 2016 campaign memo, Trump explained how he would compel the Mexicans to fork over a “one-time payment of $5-$10 billion.” Earlier this month, he reversed course, breezily declaring that “obviously” he never expected Mexico to write a check.

If all these Trump departures from Great Wall orthodoxy haven’t hurt his standing with his base, neither will agreeing to reopen the government without money for a wall — all the more so if Trump paints it not as a retreat, but as a statesmanlike decision to rescue vital government agencies from being held hostage by Democrats. Or if he signals his intention to make the wall an issue in the 2020 campaign.

The deepest reality of the Trump phenomenon is that his loyalists are passionate about him, not about his positions. It is Trump’s take-no-prisoners, burn-the-establishment persona that galvanizes MAGA Nation. Policy considerations are secondary. Indeed, survey data suggests that the desire for a wall is really a function of approval for Trump. In polls, support for the wall so tightly tracks support for Trump that it seems more plausible to conclude that the president’s base is ardent for the wall because it is ardent for him than the other way around.

Cults of personality are rare in American politics, but it is just such a cult that keeps Trump afloat. This is why he has been able to survive so many “last straws” — from insulting Gold Star families to making crude sexual boasts — that would have shattered any other politician’s viability. In an essay last fall, NBC correspondent Katy Tur recalled asking a man heading into a MAGA rally why he supported Donald Trump.

“Because he is going to build a wall,” the man told her.

“What if he doesn’t?” she asked.

“I trust his judgment,” the man said.

Trump’s base comprises millions of voters like that man, willing to follow wherever Trump chooses to lead. If he leads them to a compromise that will keep the government running, even a compromise that indefinitely defers funding for a wall, they won’t bolt.

(Jeff Jacoby is a columnist for The Boston Globe).