WASHINGTON — The departure of Steve Bannon as President Trump’s chief strategist has opened a can of worms regarding his continued influence on the direction of national policy, and Trump’s grip on his own administration.

Shortly after the press learned that Bannon was leaving the White House, he observed, “The Trump presidency that we fought for and won is over.” Only seven months into the Trump administration, it was a remarkable illustration of his own sense of self-importance, worthy of Trump’s own inflated evaluation of himself.

Bannon added: “We still have a huge movement, and we will make something of the Trump presidency. … It’ll be something else. And there’ll be all kinds of fights; there’ll be good days and bad days, but that presidency is over.”

He made it sound almost as if he were declaring occupancy of the presidency for himself through some kind of imaginary takeover, with Trump somehow continuing to function as a figurehead.

Bannon said he was “leaving the White House and going to war for Trump against his opponents — on Capitol Hill, in the media and in corporate America.” He promised to wage “a four-in-one fight” against Trump insiders Jared Kushner, Ivanka Trump, economic policy adviser Gary Cohn and National Security Adviser H.R. McMaster.

The scheme came off as the pipedream of a defecting underling with delusions of grandeur. He suggested he could achieve more through outright rebellion than he could accomplish through his previously significant power position as the president’s chief strategist.

Bannon announced he was returning to lead the alt-right website Breitbart News, from which he also would wage war on the mainstream news media, what Trump and others in his circle like to label purveyors of “fake news.” Trump and Bannon blame the media for much of the administration’s woes and chaos.

Bannon’s conceit of great influence through his radical-right website is an amazing claim. It comes amid the expanding influence in American politics of Facebook and other social media platforms, all pseudo-journalistic devices flooding today’s national discourse.

This development challenges the ability and scope of existing fact-checking entities, notably including those run by the major U.S. and foreign newspapers and magazines. They strive to hold political figures of all parties and partisan pressure groups to recognized standards of factual accuracy, even as Trump himself assaults the dialogue with his own manufactured lies and misrepresentations.

Bannon appears to be launching a bold and arrogant journalistic war on the traditional newsgathering and opinion long undertaken by the free-enterprise American press, radio and television outlets. He apparently intends to discredit, by whatever means he can, their everyday reporting and commentary product, countering it with “fake news” manufactured to satisfy his own biased political objectives.

This is truly scary stuff under a new and malfunctioning president of highly questionable moral and ethical standards. His authoritarian impulses are seen in his recent reactions to the ugly street violence brought to Charlottesville by white nationalists, neo-Nazis and other troublemakers.

Under the guise of nationalistic populism and a drive to pursue “America First” in all matters political and economic, Bannon early on tapped into Trump’s own courting of public anger and dissatisfaction with the stagnant status quo.

Now he seems to think he can be a greater force to rally Trump’s constituency of the disaffected middle and lower classes as a freelance rabble-rouser from outside the traditional political process. He even poses as a Trump ally after conspicuously deserting the ship.

Whatever the cause of Bannon’s departure from the Trump White House, his absence is a beneficial development as Chief of Staff John F. Kelly seeks a semblance of order and normalcy in an administration in extreme disarray.

The central difficulty remains in Donald Trump himself, singularly driven by self-aggrandizement and a woeful lack of vision for the nation he professes to want to make great again. This floundering president lacks any moral compass to direct him, or to encourage public confidence that he understands what has made America great already, in pursuit of a just society for all.