President Trump is mad as hell at the Associated Press. So mad, he has limited and at times even barred AP reporters and photographers from covering White House events and presidential trips. And, for the first time, AP reporters are no longer among the coveted group of “pool” reporters who attend presidential events or trips that for various reasons can’t accommodate the entire White House press corps.

The AP’s crime? Refusing to accept without qualification Trump’s decree that the international body of water known for centuries as the Gulf of Mexico is now officially the Gulf of America. The zaniness of this unilateral edict, which applies to all news organizations and, I suppose, the rest of us, calls to mind Woody Allen’s 1971 satirical film “Bananas,” in which a mad dictator seizes power in a fictional Spanish-speaking Caribbean island nation and promptly declares that “from now on our official language is Swedish.”

But this war of words between the AP and the Trump administration is no joke, nor is it just inside-the-beltway trivia.

As news consumers, we should see this for what it is: the opening shot by a grievance-driven president who feels that the “fake” media have wronged him in the past and are sure to do so in the future by being overly inquisitive about his administration’s policies. And it’s an assault that’s spreading rapidly to other highly regarded agencies, including Reuters, which, like the AP, is defying the Gulf of Mexico name change and has also seen its White House privileges curtailed.

Finally, this kerfuffle matters because a free, unrestricted press is an essential curb against unaccountable government authority. If that constitutionally enshrined right means anything, it surely can’t be that presidents get to choose who covers them or what they can or can’t write.

So why is the AP suddenly Trump’s media bête noire? In more rational times, the AP would seem among the least likely targets. Independent surveys over the years by the Knight Foundation and others have repeatedly found that the AP is regarded as among the least politically biased news organizations.

As someone who spent 18 years as an AP reporter, I know how seriously it safeguards its reputation. Among its ethical rules, AP news people who engage in political activity that casts real or potential doubt on their fairness risk their jobs. And if an editor sensed bias in any of my draft stories, it was apt to land back on my desk with a curt “says who?” note.

Get it first, but get it right. And play it straight. Those were, and remain today, watchwords at the AP that I know.

If blatant bias in the AP’s daily coverage doesn’t explain Trump’s wrath, the likelier reason is the influence AP wields in a shrinking media universe. The nonprofit 178-year-old news organization, with reporters in 93 countries and all 50 states, churns out thousands of print stories, photos and videos every day, viewed by some 4 billion people worldwide. Press Herald readers can expect to find numerous AP national, international, business stories on any given day.

There’s also the powerful influence of the AP Stylebook on many news organizations’ usage decisions. When Trump decided among his first presidential acts to change Mount Denali in Alaska back to Mount McKinley, the AP Stylebook adopted the new name since it concerned a change entirely within the geographic U.S. But the AP said its stylebook would continue to refer to the Gulf of Mexico — the majority of which lies outside U.S. jurisdiction — by the name it’s had for more than 400 years “while acknowledging the new name Trump has chosen.” And that’s what seems to have sparked this war of words.

Courts will decide who prevails. The AP has sued to regain full White House access. A federal judge ruled in February that Trump’s ban can stand for now, pending further hearings set for March 20. But the judge, a Trump appointee, also suggested that the administration might want to reconsider its position since existing legal precedent has been “uniformly unhelpful” to administrations that have tried to impose such media bans.