Is the National Enquirer Trump's mouthpiece?

Donald Trump reportedly boosts sales when he appears on the magazine's cover

It's pretty hard to avoid the National Enquirer. Sales of the downmarket US tabloid may have plummeted since a heydey in the late 1970s but its sensational celebrity headlines still shout at shoppers from the sides of checkout queues across the country.

That bit of prime real estate is where the magazine does most of its business, appealing to impulse buyers with stories of extra-marital affairs, surgeries, sudden weight losses and gains, and losses, and gains, and, increasingly, Donald Trump.

Now the Enquirer has been drawn into president's latest intrigue, after the hosts of MSNBC's Morning Joe, Mika Brzezinski and Joe Scarborough, said top White House aides told them Mr Trump would let his friends at the magazine publish a damaging story about them, unless they apologised for criticising him on air.

The president, who drew widespread condemnation after tweeting crude insults at the hosts on Thursday, denied their version of events, claiming that they contacted him for help to kill the story. Mr Scarborough says he has evidence. The story looks set to roll.

Mr Trump is a good friend to the Enquirer and vice versa. He has penned self-aggrandising first-person pieces for the magazine and can reportedly be relied on to deliver a small sales boost when he's on the cover.

He is also quite literally a friend to the magazine's owner, David Pecker, chief executive of publisher American Media Incorporated. The two have been close for decades. During the campaign, Mr Trump was the beneficiary of the magazine's first presidential endorsement in its 90-year history.

Here are some recent Enquirer cover stories on the president: "How Trump will win!"; "Trump takes charge!"; and "Trump must build the wall!".

An issue from the February before the election threatened to expose skeletons in the closets of the various presidential candidates. The Trump bombshell? "Donald Trump has also been hiding a secret - he has greater support and popularity than even he's admitted to!"

A February edition threatened to expose secrets but went soft on Trump

There was a time when the Enquirer kept mostly out of politics, preferring celebrity peccadilloes and freaky true stories instead. Then in 1987 the magazine photographed Colorado senator and presidential hopeful Gary Hart with model Donna Rice, with whom he'd been having an affair. It was a huge scoop. Mr Hart dropped out of the race.

Then in 2010 the Pulitzer Prize board conceded that the tabloid would be eligible for journalism's most prestigious prize, after a 2007 story revealed that another presidential candidate, John Edwards, had secretly fathered a daughter with a campaign staffer.

When the magazine published unsubstantiated allegations in March 2016 that Republican hopeful Ted Cruz had affairs with at least five women, Mr Trump was rumoured to be the source of the story. Then-candidate Trump denied any involvement, but couldn't resist implicitly endorsing the tale.

"Ted Cruz's problem with the National Enquirer is his and his alone," he wrote on Facebook, "and while they were right about OJ Simpson, John Edwards, and many others, I certainly hope they are not right about Lyin' Ted Cruz."

The Enquirer exposed president candidate Gary Hart's extra-marital affair

The Enquirer gunned for Mr Trump's opponents during the campaign. It diagnosed "desperate and deteriorating" Hillary Clinton with every ailment under the sun, and declared confidently that she would be "dead in six months".

As well as accusing Mr Cruz of a string of affairs, it claimed his father was involved in the plot to kill President Kennedy. Mike Huckabee was linked to hookers and Marco Rubio to a love child. Carly Fiorina was called a "homewrecker" and Ben Carson a "bungling surgeon" who "left a sponge in a patient's brain". Jeb Bush was allegedly a cocaine fiend.

"Prez Trump" meanwhile, was "winner" and "a legend", and variations on that theme.

The Enquirer's editor-in-chief, a rambunctious Australian named Dylan Howard, argues that the magazine's unstinting support for the president is driven from the bottom, not the top. He told Bloomberg that the magazine carried out an extensive poll of its readers and they overwhelmingly favoured Mr Trump.

"My duty is to my readers," he said. "I made the decision to endorse Donald Trump. Nobody influences the editorial decision-making process at the National Enquirer other than myself and our editors. We have not been told, at any point, to go easy on Mr Trump."

Whoever the matchmaker is, the Trump-Enquirer marriage looks to be in good shape. The two are a natural fit. Writing a column for the magazine during last year's campaign, Mr Trump recalled punching his music teacher in the eye "because I didn't think he knew anything about music".

"I'm not proud of that, but it's clear evidence that even early on I had a tendency to make my opinions known in a forceful way," he wrote. "The difference now is that I use my brains instead of my fists!"