Washington — PITY Poppy.

When I went down to Houston a few years ago to eat pizza with the former president, he was his usual gracious self, speaking fondly about President Obama and his new pal Bill Clinton.

But there was one person who got dismissed with a brusque obscenity: Donald Trump.

It was at the height of Trump’s birther madness and Bush was disgusted by it.

So I can only imagine 41’s dismay and disbelief — and acid flashbacks to spoiler Ross Perot — now that Trump has popped up to block the path of the son who Poppy desperately wants to see as 45, restoring the family name after 43’s spiral.

The New York wheeler-dealer, who held a fund-raiser at his Trump Tower apartment for gubernatorial candidate Jeb at Poppy’s request back in 1997, has had a devastating and disorienting effect on Jeb’s presidential candidacy.

The Trumpster has suckered Jeb! into scraps that have ended up backfiring on Jeb and elevating Trump. And he has trumpeted a lethargic, insubstantial image of Jeb that is at odds with the perky red “Jeb!” campaign logo.

In a Washington Post story last week about the fractious relationship, Trump ridiculed Jeb’s investment banking work at Lehman Brothers and later Barclays. Trump suggested that the millions Jeb was paid were a reward for steering Florida state funds to Lehman. “Why would you pay a man $1.3 million a year for a no-show job at Lehman Brothers — which, when it failed, almost took the world with it?” Trump asked.

In a bank shot, Trump dragged in the Democratic front-runner, noting, “That’s a Hillary Clinton kind of situation.”

It’s deeply weird, but the jeering billionaire reality star seems authentic to many Americans. Trump is a manifestation of national disgust — with the money that consumed politics, with the dysfunctional, artificial status quo and with the turgid return to a Bush-Clinton race, with a less adept Bush and Clinton.

“The prospect of Hillary and Jeb as the nominees created a huge opening for something like this,” said former W. strategist Matthew Dowd. “The American public looked at it and said, ‘I do not want that.’ ”

Dowd said Friday that everyone should stop being in denial and start accepting that Trump could be the nominee.

“Do I think that Trump should be president?” Dowd asked. “No. Do I think he can be the badly needed match that burns down the status quo? Yes. Do I think he could precipitate an advent of a real third party? Yes.”

He thinks the other candidates don’t know how to deal with Trump. “They should treat him like an alien visitor,” he said, “and, like judo, use his own weight — in this case, his self-absorption and hair-trigger reactions — against him. He doesn’t care if you say he’s not a real conservative.”

Trump’s “gusto,” as he likes to call it, has thrown into sharper relief the grinding-it-out, impatient entitlement, the overthinking and overcorrecting of Jeb and Hillary.

Both campaign like they are owed, not because of their great national achievements, but because of their byzantine family dynamics.

Jeb feels he is owed because his brother sneaked in and snatched the presidency that his parents had designated for the Good Son, and because he was pressured to help W. purloin Florida in 2000.

And Hillary feels she is owed because she moved to Arkansas and then stuck it out with Bill through an anachronistic first lady job and Monica; because she was a team player and bided her time in the Senate and as secretary of state; because a whippersnapper named Barack sneaked in and snatched the presidency that should have been hers.

Funnily enough, the biggest narcissist in the race — and possibly the universe — has the one slogan that refers to the desires of voters: “Make America Great Again!” Hillary has “Hillary” with an arrow pointing at it. And Jeb has “Jeb!” with an exclamation point that represents the only fizz in his campaign.

Each one of this trio has a dilemma.

Because she is seen as domineering and distant, Hillary is most popular — and becomes most human — when she is brushed back. When she is pushed against the wall, she gets better. But how can she win if she can only convey authenticity when she is losing?

She is so coiled about losing again — carrying her front-runner status around like a Fabergé egg — that she screws up and starts losing. Her server, meant to shield her image and protect her from investigation, ends up sparking an investigation and damaging her image.

Jeb has to avoid the towel-snapping tone of his brother, because that overcompensating testosterone led to tragedy. But how does he convey strength to voters fretting that America is weak and prevent Trump from painting him as a milquetoast?

Trump knows he has a dilemma as well. His hyperbolic style and instinct for the jugular have propelled him to the front of the pack — a fact that has stunned even him. But how does he keep the colored lights going while conveying requisite dignity?

Even Joe Biden, padding around the edge of the campaign, has a dilemma: How does he honor the wish of his late son, Beau, to run when the death of Beau has left him so depleted he may not be able to run?

Matt Dowd thinks Biden would do well in this field: “Trump’s the only one who can make Biden seem disciplined.”