WASHINGTON — When the National Enquirer reported without proof in March 2016 that Sen. Ted Cruz had been caught cheating with five mistresses, Cruz blamed the "tabloid smear" on "Donald Trump and his henchmen."

When the supermarket tabloid asserted two months later that Cruz’s dad took part in a conspiracy to assassinate John F. Kennedy — based on an exceedingly creative interpretation of a decades-old photo of a man who vaguely looked like the elder Cruz handing out pamphlets with Lee Harvey Oswald — Trump gleefully spread the claim to discredit his GOP presidential rival.

On Friday, The Washington Post reported that throughout the 2016 campaign, executives from the Enquirer sent copies of its articles about Trump and his opponents — including Cruz — to Trump attorney Michael Cohen for approval before publication.

One of The Post's sources said the tabloid effectively turned its editorial control "over to the Trump machine."

The claim supports Cruz's lament during the bitterness of 2016 that the Enquirer had become an extension of the front-runner's campaign, as when it "reported" that "It's over for Pervy Ted. Cruz's 5 Secret Mistresses!"

Cruz campaign officials did not respond to a request for comment Friday.

The May 2, 2016, cover of the supermarket tabloid National Enquirer, suggesting Sen. Ted Cruz's father was involved in the assassination of President John F. Kennedy.

The Enquirer's parent company, American Media Inc., denies sharing material before publication. But chief executive David Pecker is known to have a close personal relationship with Trump. Trump has written exclusives for the tabloid, and in 2013 he urged Time magazine to name Pecker its CEO.

Throughout the 2016 presidential campaign, the Enquirer aggressively supported Trump. Attacking his rivals was one technique.

At the height of the Republican primary fight, its uncorroborated articles painting Cruz as a philanderer whose father murdered an American hero seemed to be part of an effort to undermine the Texas senator — Trump’s strongest rival for the nomination.

The Enquirer's assistance wasn't confined to attacking Cruz.

This week, The Wall Street Journal reported that the Manhattan federal prosecutor subpoenaed American Media Inc. regarding a $150,000 payment in August 2016 to former Playboy model Karen McDougal for the rights to her story alleging a nine-month affair with Trump — a story it never published.

McDougal went public earlier this year, complaining she'd been the victim of a "catch and kill" maneuver by the Enquirer.

Federal authorities reportedly want to determine if that payment violated campaign-finance or other laws. It’s part of an investigation that touches on Cohen’s efforts to protect Trump during the campaign, as he did by paying adult film actress Stormy Daniels $130,000 that fall to remain silent ahead of Election Day about her own sexual encounter with Trump.

The Enquirer reported in April 2016 that Cruz's father, Rafael Cruz, a Cuban immigrant who is now a pastor, "worked with" Lee Harvey Oswald, Kennedy's assassin in Dallas on Nov. 22, 1963. The allegation was based on a photo the tabloid claimed shows the two together three months before the assassination.

Trump latched onto the story.

"His father was with Lee Harvey Oswald prior to Oswald’s being — you know, shot," Trump told Fox & Friends on the eve of the Indiana primary, when he forced Cruz from the race. “Right prior to his being shot, and nobody brings it up. They don’t even talk about that. That was reported and nobody talks about it,” Trump said. “What was he doing with Lee Harvey Oswald shortly before the death — before the shooting? It’s horrible.”

Cruz called the report "garbage" and denied that the man in the photo was his father. Few besides Trump believed it was.

The future president's willingness to inject thinly sourced tabloid fodder into a presidential campaign prompted Cruz to label him a "pathological liar."

"This is nuts," Cruz said at a campaign stop in Indiana. "The National Enquirer is tabloid trash but it's run by his good friend David Pecker, so the National Enquirer has become his hit piece that he uses to smear anybody and everybody."

"Yes,” he said, “my dad killed JFK, he is secretly Elvis, and Jimmy Hoffa is buried in his backyard."

Ted Cruz responds to Donald Trump connecting his dad, Rafael Cruz, to Lee Harvey Oswald https://t.co/B0oVg3At3N https://t.co/aypEOYCK31 — CNN Newsroom (@CNNnewsroom) May 3, 2016

Trump resurrected the story in July 2016 after Cruz refused to endorse him at the GOP convention. Having endured taunts of "Lyin' Ted," the senator said he refused to be a "servile puppy" for a rival who had attacked his father, called his wife ugly, and smeared him with a host of unsubstantiated claims.

"I know nothing about his father, I know nothing about Lee Harvey Oswald, but there was a picture on the front page of the National Enquirer, which does have credibility," Trump said after insisting that he wouldn't even accept Cruz's endorsement if one was offered.

Since Trump's election, the duo have become allies, and Cruz has touted his closeness to the president as he stumps for re-election in Texas.

The Enquirer's smear campaign against Cruz included a headline about "secret divorce details" that hinted at discord between Cruz and his wife, Heidi, but turned out to be about the divorce of Cruz's parents.

It also published attacks on Carly Fiorina, whom Cruz named his running mate six days before dropping out. The attacks called her a "homewrecker" who'd secretly undergone plastic surgery.

A former Trump adviser, Sam Nunberg, compared the tabloid to a campaign mailer. It was "such a help to Trump during the primary and even the general" election, he told The Post.