He's gone, but give Steve Bannon credit.

The former Breitbart CEO turned senior strategist in President Donald Trump's White House was one shrewd innovator in the dark arts of weaponized news, and he was able to parlay that into the biggest political upset in modern American history.

But it looks as if Bannon's skill in manipulating media might have helped spark the friendly fire that killed his political career.

It might be that this skill was what made Bannon the prime suspect when Oval Office gossip turned against the national security adviser, Gen. H. R. McMaster, as it did this month.

Were it not for neo-Nazis, North Korea, Russia, the Mooch, etc., this would have been the talk of Washington for weeks.

Day after day the Breitbart home page has opened with a story, even two, about Bannon's nemesis, McMaster — recall it was McMaster who, soon after joining the White House team, removed Bannon from the National Security Council.

Breitbart had it that McMaster is a closet globalist (Aug. 2), anti-Israel, pro-Iran and soft on terror (Aug. 3) too politically correct (Aug. 4) and unstable (Aug. 4) — "Report: H.R. McMaster 'Increasingly Volatile' and 'Frequently Blows His Top'".

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A Breitbart News logo decorates the stage where U.S. President Donald Trump addresses the Conservative Political Action Conference in Maryland on Feb. 24. (Jonathan Ernst/Reuters)

Those are just some of many examples, but the take has always been the same: the national security adviser is an enemy of the Trump agenda and a globalist with Democratic tendencies. Breitbart was relentless.

Former Breitbart staffer Ben Shapiro doubts Bannon was dictating to his former staff. He insisted to the New York Times this week that Bannon as leaker "doesn't make a lot of sense" because "it's too obvious."

But when you look at many of the Breitbart stories about McMaster they are actually sourced in other media — Politico, the Atlantic, the Jerusalem Post — and that's exactly the tactic Bannon bragged of using in the 2016 campaign, one he describes as "anchor left and pivot right."

The quote is from Devil's Bargain: Steve Bannon, Donald Trump, and the Storming of the Presidency, a page-turner for the political substance abuser by Bloomberg journalist Joshua Green. It's mostly about Bannon.

Green describes how Bannon was seeding mainstream media with anti-Hillary Clinton stories even before the 2016 campaign.

Co-opting the establishment media

Bannon realized years ago that for a news story to get "the biggest blast radius" it had to first appear in the media of the liberal establishment. And that was true even for stories attacking the liberal establishment.

Never mind all the bluff about "fake news." Bannon saw the reputation of the New York Times, for example, as a guarantee that a story from its pages would seep into other media and migrate across the political spectrum.

By contrast, stories that begin outside the establishment mainstream often don't seep anywhere but remain "trapped in the conservative ecosystem."

Bannon's biggest success was Clinton Cash: The Untold Story of How and Why Foreign Governments and Businesses Helped Make Bill and Hillary Rich, which alleged corruption in the Clinton family and from which pre-publication story lines were exclusively shared with the New York Times and the Washington Post.

Clinton Cash was written by Peter Schweizer, but Green reports the mastermind behind the whole project, including its rollout, was Bannon.

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Trump talks to Bannon during a swearing-in ceremony for senior staff at the White House on Jan. 22. Several Bannon allies with lines to Breitbart remain in the White House, but for how long? (Carlos Barria/Reuters)

In any case, Bannon just doesn't sound like a guy who could cut himself off from the place where he used to work at the moment it's covering the place where he now works — or did until Friday. He even had a waiver from government ethics rules that allowed him to contact Breitbart whenever he wanted.

So with all of that happening around him, is it any wonder McMaster and his friend, the new chief of staff Gen. John Kelly, would see a problem and resolve to fix it?

More enemies: The Trump family

Bannon's enemies beyond the generals are understood to have come to include the Trump family who, understandably, believe that only they truly have their father's interests at heart.

Whether Bannon's exit signals a divorce from other members of the Breitbart wing of Trump's base will become clear over time.

The billionaire Robert Mercer and his daughter Rebekah were key backers of Trump's campaign and investors in Breitbart. It was they who insisted Bannon take control of Trump's campaign last summer and that he bring on Kellyanne Conway. How will that play out?

There remain in the White House other Bannon allies with lines to Breitbart. Sebastian Gorka, who sometimes seems he could have a role in The Adventures of Rocky & Bullwinkle, is the foreign affairs adviser to the president. He holds a PhD that's been described by serious academics as "mail order" level and was once national security editor for Breitbart. Is he long for his White House job?

Generals vs. Valkyries?

Julia Hahn, a special assistant to the president, is ex-Breitbart. She was one of three reporters that Bannon dubbed "the Valkyries." In Devil's Bargain Bannon says of Hahn, "when she comes into your life, shit gets f...ed up."

It's possible the generals won't want their shit f...ed up.

They apparently didn't want someone who enjoys thinking about the "blast radius" when leaking news stories and they put an end to it.

It seems a long time ago (or was it only yesterday?) that White House officials were clutching their pearls about leakers and threatening dire consequences if they ever caught one.

It seems they finally have. Must feel good.

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Bannon looks out a window of Air Force One at Joint Base Andrews, Md., on Feb. 12. His enemies are understood to have come to include the Trump family. (Carlos Barria/Reuters)