Donald Trump thinks The Washington Post treats him unfairly. The presumptive Republican presidential nominee says the same about the media, in general, but he singled out the newspaper Thursday night because of The Post's ongoing book project examining his life and career.

Trump told Fox News's Sean Hannity that the book is part of an elaborate plan by Post owner Jeffrey P. Bezos, the founder of Amazon. The plan goes like this, according to Trump: Bezos bought The Post for “practically nothing” ($250 million) and is using the paper to keep Trump out of the White House because Amazon has “a huge antitrust problem,” and Bezos “thinks I would go after him for antitrust.”

Post Executive Editor Martin Baron said Bezos has engaged in no such plotting: “As the individual who oversees The Washington Post’s news staff, I can say categorically that I have received no instructions from Jeff Bezos regarding our coverage of the presidential campaign — or, for that matter, any other subject. The Post has a long tradition of publishing thorough examinations of the major party nominees for president. The decision to write a book on Donald Trump came entirely from the newsroom.”

Trump first attacked Bezos in December, alleging that The Post — which Bezos owns through an investment firm that is separate from Amazon — somehow serves as a "tax shelter" for the technology giant. Trump's theory seems to be that Amazon could lower its tax obligation by claiming a deduction for The Post. But Amazon doesn't own The Post; Nash Holdings, Bezos's private investment company, does. The two entities are taxed separately. The Post's business performance, therefore, does not affect Amazon's taxes.

What's more, Amazon has lobbied in favor of online sales taxes. That might seem counterintuitive, and competitors such as eBay have taken the opposite position. But one motivation, as NPR's "Planet Money" explained in 2013, could be that having to collect sales taxes — which vary state to state — is a hassle that might discourage start-ups from trying to disrupt the online retail marketplace, in which Amazon is a major player.

Bezos, an infrequent Twitter user, responded to Trump's initial charges in December by offering to send him to outer space.

So what's this latest, antitrust thing about? Trump didn't go into specifics with Hannity. He could be thinking of long-standing complaints by some book authors that Amazon wields too much power in the electronic publishing industry. One group of writers, Authors United, asked the Justice Department to investigate Amazon for monopolistic practices in the summer. But the Justice Department, which sued Apple in 2012 for conspiring with book publishers to raise the prices of e-books (Apple will pay $450 million under a settlement), so far has not found grounds for a similar case against Amazon.

Fortune declared in August that the authors' effort to convince the Justice Department to pursue an antitrust case is "doomed."

Given the foundering status of the e-book complaint, it is possible that Trump was referring to something fresher — Amazon's decision in the fall to stop selling video streaming devices from Apple and Google that compete with its own Fire line of products. The move was ostensibly due to the incompatibility of Apple TV and Google Chromecast with the Amazon Prime service, but it was widely viewed as an attempt to seize a larger share of the growing market for streaming video, in which these West Coast technology titans are fierce rivals.

Los Angeles Times columnist Michael Hiltzik wrote at the time of Amazon's announcement in October that "by banning rivals from its shelves, Amazon is acting like a wannabe monopolist." But even as he leveled criticism, Hiltzik added this:

It's doubtful that Amazon's move rises to the level of an antitrust violation, because the banned products remain widely available. Apple owns nearly 300 stores in the U.S. alone, and Google sells Chromecast through other retailers and online. Both offer their products online.

Marketplace also addressed the antitrust question:

As news of Amazon’s move spread, some social media commenters questioned whether Amazon could face antitrust action. NYU law professor Scott Hemphill doesn’t see a strong case. And he was previously antitrust bureau chief for New York’s attorney general, so he’s always on the lookout for a good court battle. Actually, when Amazon and other powerful companies play hardball with each other, it can be pretty cool.
“These attacks on each other’s strongholds, we should applaud that,” Hemphill said. “The benefits for innovation and ultimately for consumers are potentially quite large.”

Trump told Hannity that Bezos is "worried about me," by which he presumably means Bezos is worried that President Trump's Justice Department would bring an antitrust suit against Amazon that President Obama's Justice Department has declined to file. The Post, in this scenario, is Bezos's firewall — here to block Trump from reaching the Oval Office, thereby protecting Amazon from antitrust litigation.

But if Bezos was worried about Trump's antitrust tendencies when he struck a deal to buy The Post in August 2013, he had tremendous foresight. Trump didn't launch his presidential campaign until 22 months later.