By their endorsers shall ye know them.

That variation on a Gospel maxim was inspired by a radio campaign commercial now airing throughout our state.

And as civic-minded South Carolinians do their due diligence before deciding which candidate gets their vote in which presidential primary (Feb. 20 for Republicans, Feb. 27 for Democrats), they should consider not just the competitors’ endorsers but their friends and relations.

For instance, Jerry Falwell Jr., president of Liberty University in Lynchburg, Va., endorsed GOP front-runner Donald Trump last month. And Falwell gets the aforementioned Bible verse word-for-word correct in that current radio ad with this political pitch:

“Matthew 7:16 tells us, ‘By their fruits, you shall know them.’ Donald Trump’s life has borne fruit.”

But how much more of what “The Donald” sows can we bear?

During his speech at Liberty last month, Trump delivered what was, coming from him, especially exalted praise for the Good Book. He pointed out that is the all-time best-seller, eclipsing even his “The Art of the Deal.” Trump then added my favorite line of the campaign (so far): “The Bible blows them away. There’s nothing like it, the Bible.”

There’s also nothing like using guilt by association to malign a political opponent.

During Thursday night’s Democratic debate in Milwaukee, Bernie Sanders said that in Hillary Clinton’s “book (2014’s “Hard Choices”) and in this last debate, she talked about getting the approval or the support or the mentoring of Henry Kissinger. “

Sanders continued: “Now I find it rather amazing, because I happen to believe that Henry Kissinger was one of the most destructive secretaries of state in the modern history of this country. I am proud to say that Henry Kissinger is not my friend. I will not take advice from Henry Kissinger.”

Clinton gamely responded: “Well, I know journalists have asked who you do listen to on foreign policy, and we have yet to know who that is.”

Sanders, right back at her: “Well, it ain’t Henry Kissinger. That’s for sure.”

If you think that was contentious, just wait until the Republicans go at it during tonight’s debate in Greenville.

Some of them will even accuse their in-party rivals of consorting with — brace yourself — Democrats.

In 2008, Democratic nominee Barack Obama was repeatedly chastised (though not by GOP nominee John McCain) for long attending the Chicago church where the Rev. Jeremiah Wright delivered what many regarded as some anti-American sermons.

That is, if you deem shouting “xxx-damn America!” as anti-American.

In 2004, an ad from the Media Fund (Harold Ickes, George Soros, et al.) showed the Saudi royal family, then showed photos of both Presidents Bush with some of its members, as a stern voice told viewers: “Wealthy. Powerful. Corrupt. And close Bush family friends.”

Also in 2004, a Swift Boat Veterans for Truth ad showed Jane Fonda in Hanoi, then John Kerry testifying about U.S. “war crimes” on Capitol Hill.

OK, so Vietnam vet Kerry shouldn’t have dumped on our country — and his former comrades in arms — that way.

Yet now that Kerry has brought peace to Syria (or has he?), he should come our Charleston area way to mediate bitter disputes over Shem Creek, Summerville’s town government, the Sgt. Jasper site and the proposed bike lane over the Legare bridge over the Ashley River.

Or should we invite Kissinger instead?

1) Name the presidential relative who got a large loan from Moammar Gadhafi’s Libyan regime.

2) Name the Key Biscayne resident who was investigated, but never charged, over allegations of taking large payments as a “bag man” for his longtime pal who had become president.

3) Name the mock movie poster that features Kissinger as one of the good guys.

1) Billy Carter’s trips to Libya and the $220,000 loan he received from the Gadhafi government triggered a Senate investigation of suspected influence peddling. Though no charges were filed, “Billygate” was another unsettling bump in the 1980 road for Jimmy Carter, who later that year lost the White House — and 44 states — to Ronald Reagan.

2) Charles “Bebe” Rebozo became friends with then-California Congressman Richard Nixon in 1950. Rebozo, a wealthy wheeler-dealer, later became Nixon’s financial adviser. Nixon, as president, set up a “Winter White House” near Rebozo’s swank Key Biscayne pad. Nixon’s former place plays the house of Frank Lopez (played by Robert Loggia) in the 1983 movie “Scarface,” which stars Al Pacino.

3) “Bedtime for Brezhnev” is a 1981 parody movie poster, created by Harvard Business School students John Freund and David Porter. Billed as a production of “Free Enterprise Films,” it’s a spoof on “Bedtime for Bonzo,” the 1951 cinematic comedy classic starring Reagan as a college psychology professor who raises a chimpanzee (the title character) to test the relative impacts of heredity and environment.

The “Bedtime for Brezhnev” poster shows Reagan, in cowboy garb with a white hat, grabbing the title-character Soviet tyrant, who of course wears a black hat. Across the top of the poster are these thrilling words:

“From out of the west, they dusted off their guns ... to protect the world they knew and the women they loved!”

The poster also displays mug shots of the co-stars (again, good guys in white hats, bad guys in black hats), including the first President George Bush, Gen. Alexander Haig and “Henry Kissinger as ‘Doc.’ ” The bad guys: “Comrade Fidel Castro, Chairman Leonid Brezhnev and Colonel Moammar Khadafy [same villain as Gadhafi, different spelling].”

And: “Co-starring Nancy Davis” ... “Based on an original concept by Barry Goldwater” ... “and introducing Jerry Brown as ‘the preacher.’ ”

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