Battleground polling of the blue-wall states so pivotal to Democratic hopes show former President Donald Trump in a best-case scenario.

CBS’s survey released Sunday shows Pennsylvania tied, with Vice President Kamala Harris up by 1 point in Michigan and 2 points in Wisconsin.

The 44 electoral votes that hang in the balance in these states are ripe for the taking.

And depending on how Trump approaches Tuesday’s debate in Philadelphia, he may be positioned to pick them off.

The question, of course, is what version of Donald Trump viewers get.

In his nearly decade of debate appearances, we’ve seen a number of game plans.

Some will work better than others.

In 2016, a radically different era, Trump got away with “looming behind” Hillary Clinton, as she put it in her memoir written after she lost the race.

She admitted the strategy rattled her and expressed regrets over not calling it out in real time.

Rest assured Harris, who like Clinton is predicating her campaign on breaking a metaphorical glass ceiling, would relish the opportunity to create a moment to put Trump in his place — which would likely be far more memorable than the policy sparring in the rest of the event.

So Trump must avoid a repeat of 2016.

And the best way to do that is take a page from arguably the most successful debater in GOP presidential history: Ronald Reagan, the man from whom Trump literally ripped off Make America Great Again.

Trump has already had and wasted one opportunity to pivot in the campaign.

In the wake of the summer assassination attempt on him in Butler, Pa., the former president could have delivered a radically different convention speech than he did — a more aspirational address showing he’d been transformed instead of a few minutes of new material grafted onto the standard rally speech.

This time around, viewers expect Trump will be surly, combative, cantankerous, truculent — as he generally has been since he entered politics.

He needs to subvert that narrative.

Trump has one of the best senses of humor in politics — he’s the rare Republican who can deliver a joke with a punchline.

And he must do what the last Republican who could tell a joke — Reagan again — did.

It’s possible, for example, Trump’s age becomes an issue with the octogenarian Joe Biden off the stage. We know how the Gipper handled that against Walter Mondale in 1984: “I will not make age an issue of this campaign. I am not going to exploit, for political purposes, my opponent’s youth and inexperience.”

The former prez also should be prepared with some routines about Harris’ more unmoored phrasings, including her infamous calls to Americans to be “unburdened by what has been.”

Reporters will never be able to ask her what she means by that particular serving of word salad. But Trump can. (Rhetorically, at least — Tuesday’s rules say candidates aren’t supposed to question each other.)

He can ask why, in a change election, the avatar of the Democratic status quo is delivering aspirational goo instead of real solutions for policy problems that emerged during the Biden presidency.

The ultimate Ronald Reagan tribute, however, would be the simplest. And it should be reserved for the closing statement: “Are you better off than you were four years ago?”

Sentence by sentence, it’s as relevant as it was nearly a half-century ago, and it’s ready for Trump’s appropriation.

“Is it easier for you to go and buy things in the stores than it was four years ago? Is there more or less unemployment in the country than there was four years ago? Is America as respected throughout the world as it was? Do you feel that our security is as safe, that we’re as strong as we were four years ago? And if you answer all of those questions yes, why then I think your choice is very obvious as to who you’ll vote for. If you don’t agree, if you don’t think that this course that we’ve been on for the last four years is what you would like to see us follow for the next four, then I could suggest another choice that you have.”