Any mention of “the speech” at a GOP convention sends memories racing back to Ronald Reagan’s surprise address in 1976. He had lost the nomination in a bitter fight with President Gerald Ford, who hoped to unite the party by summoning Reagan to the podium for brief remarks.

The result was Reagan’s stirring, seven-minute address about securing individual liberty that left many delegates convinced they had, as author Craig Shirley wrote, “nominated the wrong man.”

Events would show they had, and the Reagan Revolution that was born that night and took root four years later made the speech the gold standard of convention addresses.

It’s a template for what Donald Trump must accomplish with his acceptance speech Thursday night. He needs to do something he’s never done, and that many people think he cannot do.

Before the red, white and balloons drop at the Quicken Loans Arena and his family joins him onstage for the celebratory photo ops, Trump must convince about 65 million Americans that he is ready and able to be president.

Establishing that belief in voters’ minds is the ultimate purpose of a convention. When it happens, the process is a quasi-religious conversion. Instead of a mere candidate, the nominee takes on the aura of a potential president-in-waiting. From that point on, the campaign is more of a quest than an experiment, and the possibility of victory becomes realistic.

That conversion is absolutely necessary in Trump’s case because of widespread doubts that he is fit for the Oval Office. His lack of experience, combined with missteps, misstatements and a tendency to shoot first and aim later leave him with a steep hill to climb.

Although polls show that the race is tight and that Hillary Clinton is widely viewed as dishonest, she enjoys an Electoral College advantage, as well as a personal one. Her proximity to presidential power and decades in top government positions make it easier for many voters to at least imagine her sitting in the Oval Office.

More than a majority of voters say they simply cannot imagine Trump as president. His challenge, then, is to change millions of minds with the speech of his life.

He should not try to be all things to all people, but he must reveal a man fully ready to lead the nation for all occasions.

The effort to transform him already has started here. While rip-roaring speeches from Rudy Giuliani, Chris Christie and many others took the fight to Clinton, Trump’s wife and children used their time onstage to humanize him.

Their heartfelt testimonies to his love and kindness and seriousness of purpose aim to bathe him in a softer, warmer light, while their well-received addresses also make him look good as the father of such smart and loving children.

Melania, too, did her part in remarks that were praised until the storm of charges over plagiarism drowned out what she said and how she said it.

Yet none of that will matter if Trump himself fails to meet the moment. The land mines are everywhere, and stepping on one or two could make his quest next to impossible.

For starters, this can’t be just another rambling speech about himself. At this point, nobody cares about his company and his wealth, and this is certainly not the time to settle scores and hurl insults.

This is the time to talk about America and his vision for guiding the nation through a forest of crises, foreign and domestic. It should emphasize principle over policy, and be uplifting.

Instead of talking about himself, he must show himself by talking about the people whose votes he already has and those he needs. He must speak to their concerns and their dreams in ways that demonstrate he will faithfully represent Americans of all tribes, beliefs and places.

He got to this remarkable station by earning the trust of millions and understanding they felt abandoned by both parties; now he must add to their confidence and numbers by pledging to work for them and them only. They must know that they will be his lodestar in the White House.

Above all, every word he says must come from the heart. Anything that doesn’t will clang like a loud warning signal that he’s not ready. Ad libs are dangerous at this stage.

The Clinton team is busy trying to paint him as toxic and dangerous and make him an unacceptable alternative. His mission is to peel off that paint and convince voters he is at least every bit as worthy of the office they both seek.

There is, of course, a vital difference between events of 1976 and Trump’s mission. Reagan was fighting for the future, Trump’s future is now. Whether he has one largely depends on how he handles his turn at “the speech.”