Lindsey Graham called Donald Trump a “jackass” Tuesday.

Later that day, Trump called Graham “an idiot.”

Similar insults, but a crucial distinction:

Trump is a jackass.

Graham is not an idiot.

And Graham’s self-administered, energetic destruction of his cellphone in a video released Wednesday, in response to Trump revealing its number Tuesday, further escalated their feud toward a potential “Loser leaves GOP Field” grudge match.

As for the galling notion that Trump is a Republican, Graham’s choice of pejorative subtly enhanced its meaning.

After all, a jackass is a male donkey. And the donkey is the Democratic Party’s mascot.

And according to a July 9 posting on the Tampa Bay Times’ PolitiFact.com, based on data from the Federal Election Commission and various states’ election offices, Trump has given $584,850 to Democrats over the last 26 years.

Yes, “The Donald” also gave $961,140 to Republicans over the same period. Then again, as PolitiFact also reported: “The difference in donations is almost entirely captured in Trump’s recent giving.”

In other words, Trump is no Barry Goldwater.

Nor is he following Ronald Reagan’s Eleventh Commandment: “Thou shalt not speak ill of any fellow Republican.”

Sure, vigorous intra-party debate is essential. But Trump crossed the party line — again — on Tuesday when he said this about Graham to a gathering in Sun City Hilton Head:

“Here’s a guy — in the private sector he couldn’t get a job. Believe me. Couldn’t get a job. He couldn’t do what you people did. You’re retired as hell and rich. He wouldn’t be rich; he’d be poor.”

Hey, unlike Trump, Graham came from humble circumstances.

Also unlike Trump, Graham served in the military, as did his venerable buddy and mentor John McCain.

So the offense that sparked Graham’s “jackass” outburst came last Saturday when the blustering billionaire said of McCain: “He’s a war hero because he was captured. I like people that weren’t captured.”

Trump later conceded that “perhaps” McCain is a war hero.

Regardless of how you define “hero,” however, Trump’s defining the very-early GOP White House race and leading the too-early polls — though faring worse than several other Republicans in head-to-head matchups with Hillary Clinton.

Meanwhile, Graham, again unlike Trump, isn’t going to make the goofy, poll-determined cut (top 10 in the 16-candidate field) for the first debate Aug. 6 in Cleveland.

At least Graham is in the Aug. 3 GOP forum, co-sponsored by The Post and Courier, in Manchester, N.H.

At least Graham, by drawing Trump’s verbal fire, has gained needed national notice.

And at least Graham remains the most well-informed, persuasive and generally impressive politician who has crossed my long and winding newspaper-person road.

OK, so a week ago today my column — “The hour grows late for Graham’s bid” — poked fun at him for “trying to expand his so-far sparse audience” as the final guest on NBC’s “Late Night with Seth Meyers” two nights earlier.

An astute reader countered that lots of big-time politicians have shown up in that 12:35-1:35 a.m. time slot.

For instance, Vice President Joe Biden, the most likely alternative to Mrs. Clinton if — or is that when? — Democrats realize that she’s too unlikable to be elected president, was on Meyers’ 2014 “Late Night” debut.

Back to more of Trump’s tripe in Sun City: “I see your senator, what a stiff. What a stiff — Lindsey Graham.”

Hmm. S.C. voters have elected Graham to the U.S. Senate three times by an average margin of 14 percentage points.

So even if you’ve never voted for Graham, keep in mind that when Trump calls him an “idiot” and a “stiff,” he’s not just dumping on our senior senator.

He’s dumping on some of your friends and neighbors — and maybe family members.

Now for closing samples of pungent putdowns, the first three from Brits, far more creative than “stiff,” “idiot” and even “jackass”:

“An empty taxi arrived at 10 Downing Street, and when the door was opened, [Prime Minister Clement] Attlee got out.” — Winston Churchill

“Attila the Hen” — British MP (Member of Parliament) Sir Clement Freud (grandson of Sigmund) on Prime Minister Margaret Thatcher, my favorite female politician (and second behind only her pal Ronald Reagan as my overall favorite)

“He’s living proof that a pig’s bladder on the end of a stick can be elected to Parliament.” — Labor MP Tony Banks on Conservative MP Terry Dicks

“So thank you, Seth Rollins, for being such a conniving, slimy, weasel-faced, suck-up, sellout, poor excuse for a champion.” — U.S. champion John Cena, in mock gratitude to World Wrestling Entertainment champ Seth Rollins (no known relation to Seth Meyers) on this week’s “Monday Night Raw”

And much closer to home, then-Sen. Ernest F. “Fritz” Hollings, responding to a challenge by Republican nominee (now Lt. Gov.) Henry McMaster in a 1986 debate:

“I’ll take a drug test when you take an IQ test.”

Frank Wooten is assistant editor of The Post and Courier. His email is wooten@postandcourier.com.