You’re in the grocery checkout line, and there they are: The photos. The headlines.

“Back Together at Last! Brad & Jen: We Want a Baby!”

That is completely untrue, your rational mind says as you pick up the tabloid. Brad Pitt and Jennifer Aniston were done years ago. As if they’d ever get back together. Besides, you remind yourself, Aniston is 50. Could she still have a baby at 50?

“Next!” the cashier shouts. You stuff the gossip rag back on the rack, hoping nobody noticed.

Such is the tabloid landscape populated by the National Enquirer and its stablemates, the National Examiner and the Globe, as well as the glossies Us Weekly, OK, Star, Closer, InTouch and Life & Style.

Though their circulation has been decimated — the once-mighty National Enquirer, which approached 8 million in paid circulation at one point, is down under 180,000, according to industry monitor the Audit Bureau of Control — tabloids still occupy a unique place in American culture.

The National Enquirer’s original mass-appeal magic came from publisher Generoso Pope Jr., said 20-year tabloid veteran John Isaac Jones, author of the 2014 book “Thanks, PG! Memoirs of a Tabloid Reporter.”

“It was the classic definition of kind of a lowbrow Reader’s Digest,” Jones said. Pope “read all the mail. He knew what kind of stories to play. And he was an absolute master at it.”

The National Enquirer’s advertising media kit touts a median reader age of 50.6 and a median reader household income of just under $60,000 a year.

Magazine sales, including the tabloids that arrive each Tuesday, are down 11% year-over-year at the Ralphs supermarket chain, said John Votava, director of the company’s communications. Still, that’s No. 3 in the general-merchandise category, after cigarettes and greeting cards. The celebrity publications sell for $5 or $6 a pop.

“You’ve got that impulse buy at the register,” Votava said. “People see that headline, they’re like, ‘Oh, this looks like fun, I could take this home and read this.’ ”

O.J. changed everything

The industry turned in 1995, spurred by the cultural phenomenon that was the O.J. Simpson trial, according to Jones.

“When everyone saw how popular O.J. was on television, everybody else jumped on the bandwagon,” said Jones, who started working for the Enquirer in 1977.

Post-Simpson, the things that had been sturdy tabloid staples — stars, scandals and sex — started showing up in the mainstream media. It was the beginning of the end for the tabloids, a decline that was accelerated by the arrival of the internet.

“The National Enquirer as it’s printed today is a very poor resemblance of the Enquirer of G.P.’s day,” Jones said.

Much of what appears in the tabloids now is of sketchy veracity. When Jones was a reporter, he said, interviews had to be recorded, and those recordings went through a fact-checking department. Today, stories run without bylines and most sources are anonymous “insiders.” A far-fetched plot will be put forth in great detail, with a short denial by a publicist slipped in near the end.

Walking a fine line

So why don’t the celebrities and politicians who are the subject of the fabricated stories sue? Because it usually isn’t worth it, said Kavon Adli, an attorney with the internet Law Group. Making up a story isn’t against the law unless it crosses the line into libel, something most tabloids are very careful to avoid.

“If celebrities were to sue every tabloid that had a false story, it would become prohibitively expensive,” Adli said. Often stars simply trust that the public knows tabloids “have a reputation for sensationalism.”

The fact-checking website Gossip Cop investigates nearly every story in every tabloid. Each story gets a rating, from zero (false) to 10 (true). There are a lot of zeros.

“We do careful research and due diligence to avoid getting things wrong,” editor Andrew Shuster said. “Some stories are flat-out fabricated while others have kernels of truth, and we’ll acknowledge that.”

What does the Gossip Cop team get tired of debunking?

“There are often recurring themes that have more in common with a bad soap opera than they do with journalism,” Shuster said. “Jennifer Aniston seems to be pregnant with Brad Pitt’s baby on a nearly weekly basis.”