Donald J. Trump, the presumptive GOP nominee for president, has given us one more reason to call into question his judgment.

On June 13, Mr. Trump revoked the The Washington Post’s credentials to cover his campaign events.

That may be a relief to the unlucky journalist who drew the short straw and found himself or herself assigned to cover a Trump rally even for a few hours. Trepidation — for a host of reasons — best describes the pervasive feeling that enshrouded the Richmond Free Press newsroom when it was learned Mr. Trump was coming to RVA.

Nevertheless, kicking journalists out of America’s biggest, most important salute to democracy — a presidential campaign culminating in a national election — is, well, un-American. It shows Mr. Trump’s flagrant disregard for the importance of a free and independent press and borders on disdain for the U.S. Constitution and First Amendment rights.

Unhappy with a Washington Post headline on an article about his statements following the Orlando mass shooting, Mr. Trump posted this to Facebook: “Based on the incredibly inaccurate coverage and reporting of the record setting Trump campaign, we are hereby revoking the press credentials of the phony and dishonest Washington Post.”

Denying The Post access to his campaign events is only Mr. Trump’s latest attempt to control the media. Previously, he banned a number of news outlets from attending his events and press conferences, including Politico, The Huffington Post, Univision, Mother Jones, the Des Moines Register, the New Hampshire Union Leader, Buzzfeed, Foreign Policy, Fusion, Gawker and the Daily Beast.

In a recent TV interview, he accused Amazon founder Jeffrey P. Bezos of using his ownership of The Post to deflect scrutiny of Amazon’s taxes and suggested he would launch an antitrust investigation of Amazon if he becomes president.

Undeterred, The Post and other news organizations refuse to be squelched and have continued reporting on Mr. Trump’s activities.

Donald Trump is dangerous. Rather than adhering to the principles set up under the Constitution and going by the laws of the land, Donald Trump makes up his own rules — and breaks those, too, when he wants.

History has shown us how fascists and dictators have moved to control and shut down the independent media when they come to power.

What happens when, if president, Mr. Trump gets really tough questions?

This is only the latest example of the clear and present danger he represents.