Bill Sternberg

USA TODAY

Donald Trump turns 70 on Tuesday, and many Republicans seem to be hoping (praying?) for a later-in-life metamorphosis. “He’s going to have to stop with gratuitous personal insults,” said Sen. Susan Collins. “He will have to earn the presidency by demonstrating that he has the temperament for the job,” added Rep. Cathy McMorris Rodgers.

Sound advice, no doubt. But expecting Trump to change significantly as he enters his eighth decade is like marrying a man and expecting to reform all the qualities you don’t like. Ask any wife about the prospect of that happening. “Savior complex” projects rarely succeed. At 30. Or 50. Much less at 70.

If elected, in fact, Trump would be the oldest person to assume the presidency, topping Ronald Reagan, who was 69 when he took the oath of office in 1981. Like 74-year-old Bernie Sanders, Trump has run a remarkably high-energy campaign, careening from nighttime speeches to interviews on the early-morning talk shows.

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According to his longtime personal physician, the billionaire businessman had “astonishingly excellent” blood pressure and lab test results in his latest exam, shows “extraordinary” physical strength and stamina, and “will be the healthiest individual ever elected to the presidency.” The statement was attributed to Dr. Harold Bornstein, though it reads more like something you’d get from the Kremlin about Vladimir Putin, or a news release from some future Trump College of Medical Knowledge.

The main concerns about Trump, of course, aren’t physical. They’re psychological.

“Across his lifetime, Donald Trump has exhibited a trait profile that you would not expect of a U.S. president: sky-high extroversion combined with off-the-chart low agreeableness,” Dan P. McAdams, a psychology professor at Northwestern University, writes in The Atlantic. Trump, McAdams adds, exhibits classic signs of grandiose narcissism.

Narcissists can sometimes achieve great things. They also need to hog the spotlight, often by saying or doing outrageous things. They act like they are always on stage. They demonstrate low empathy for others. They seek out enemies to insult. Ultimately, everything’s about them.

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The candidate’s @realDonaldTrump Twitter feed serves as a sort of direct line to his mind, so it wasn’t surprising that soon after Sunday’s massacre in Orlando he tweeted about … Donald Trump: “Appreciate the congrats for being right on radical Islamic terrorism.”

A year after he entered the race for the White House, can Trump shift political tactics as he moves from the primary campaign to the general election? Sure. But anyone expecting Trump to suddenly pivot to a more traditional presidential demeanor should remember that social scientists say personality is relatively consistent and stable after the age of 30. That’s one reason the “new” Richard Nixon who ran for president in 1968 turned out to be a lot like the old Nixon. Moreover, the longer that people hold certain beliefs, the more likely they’ll ignore evidence that contradicts those beliefs.

And from Trump’s point of view, even if he could execute an extreme makeover at his relatively advanced age, why should he? Confounding the pundits and ignoring the experts, he bested 16 GOP rivals and captured his party’s presidential nomination by doing things his way.

Not that people are giving up. "I think he ought to change direction, and I hope that’s what we’re going to see,” Senate Majority Leader Mitch McConnell told Bloomberg Politics this month.

Good luck with that.

In Just the Way You Are, Billy Joel sings, “Don’t go changing to try and please me.” With septuagenarian Donald Trump, there’s not much chance of that happening. Just ask him. “You think I’m going to change?” he said at a news conference last month. “I’m not changing.”

Bill Sternberg is editor of the editorial page. Follow him on Twitter @bsternbe.