Steve Bannon, the ousted White House chief strategist, is reportedly considering starting a television network which would allow him to "go nuclear" as he settles vendettas with moderate advisers in the White House and pressures President Donald Trump to pursue a populist agenda of economic nationalism.
Allies of Mr Bannon compared him to a "tiger freed from his cage," suggesting things would get "ugly" as he targets the Republican establishment and what he calls "West Wing Democrats".
The departure of Mr Bannon came amid one of Mr Trump's worst weeks as president.
He and first lady Melania Trump decided not to participate in the annual Kennedy Center Honours event celebrating American culture after a backlash from those being honoured. The White House said the first couple were pulling out to "allow the honourees to celebrate without any political distraction".
I want to thank Steve Bannon for his service. He came to the campaign during my run against Crooked Hillary Clinton - it was great! Thanks S— Donald J. Trump (@realDonaldTrump) August 19, 2017
Meanwhile, a host of charities canceled annual fundraising events at Mr Trump's Mar-a-Lago resort in Florida. They included the American Red Cross, Salvation Army, and the American Cancer Society.
Mr Bannon's possible TV network would be intended as a rival to Fox News, the Rupert Murdoch-owned channel which has been supportive of Mr Trump, but which Mr Bannon now regards as too moderate, Axios reported.
Immediately after his departure on Friday he re-assumed control of Breitbart, the influential right-wing news website he steered before joining Mr Trump's campaign last year. Mr Bannon said he was "going to war for Trump," which appeared to mean the original hard line policies pursued during the campaign.
Mr Bannon's new venture would probably be funded by Bob Mercer, the hedge fund billionaire and conservative mega-donor, who has previously backed both Breitbart and Mr Trump. Mr Mercer and Mr Bannon met last week to discus plans for after his White House exit. The following evening Mr Mercer had dinner with the president.
On the outside Mr Bannon will target a ring of presidential advisers sometimes known as the "globalists". It includes Jared Kushner and Ivanka Trump, chief economic adviser Gary Cohn, Treasury Secretary Steve Mnuchin, and National Security Adviser H.R. McMaster, with whom Mr Bannon appeared to have lost a battle over putting more troops in Afghanistan.
Also in the firing line are Republican leaders in Congress such as House Speaker Paul Ryan and senate Majority Leader Mitch McConnell, Republicans who Mr Bannon blames for stalling Mr Trump's agenda, including funding for the border wall, and failing to overturn Obamacare.
Mr Bannon has few allies left within the White House promoting his agenda of economic nationalism. There was speculation that the few who remain, including senior policy adviser Stephen Miller, and deputy assistant Sebastian Gorka, could be purged by John Kelly, the new chief of staff who is seeking to bring order to the chaotic administration.
Mr Kelly's authority over the White House was boosted by Mr Bannon's departure. A triumvirate of military generals - Mr Kelly, Mr McMaster, and Defence Secretary James Mattis - now hold extraordinary sway within the administration.
Sam Nunberg, a former Trump campaign adviser and friend of Mr Bannon, said: "It's a tough pill to swallow because you have a Republican West Wing that's filled with generals and Democrats. It would feel like the twilight zone."
In a candid first interview after leaving, Mr Bannon told the Weekly Standard: "The Trump presidency that we fought for, and won, is over. The Republican establishment has no interest in Trump’s success. They’re not populists, they’re not nationalists, they had no interest in his programme. Zero. They’re going to try to moderate him."
Mr Bannon added: "I feel jacked up. I've got my hands back on my weapons. It's Bannon the Barbarian. I am definitely going to crush the opposition. I built a f****** machine at Breitbart. We're about to rev that machine up.”
A friend of Mr Bannon told The Atlantic: "Steve is now unchained. He’s going nuclear. You have no idea. This is gonna be really f****** bad."
Mr Bannon's removal was hastened by his growing public profile as a leader of the populist right, which had begun to irk Mr Trump. That included Mr Bannon being on the cover of Time magazine. Mr Trump was also reportedly angered by a book called Devil's Bargain portraying Mr Bannon as the architect of his election win.
Josh Green, the book's author, spoke to Mr Bannon immediately after he left the White House, and said he was full of "manic" energy.
Mr Green said: "Bannon sounded like he'd just consumed 40 Red Bulls. He's a tiger being let out of his cage. I think he'll still have Trump's ear. Bannon's great disappointment is that the White House hasn't been able to deliver on a lot of things they promised. In his view that is because people in the White House are inhibiting Trump. He wants to exert pressure from the outside and steer Trump back to the polices he ran on."
But Steve King, a conservative Republican congressman from Iowa, said: "I don’t have any longer the expectations that Trump can keep the rest of his promises."
Mr Trump waited a day before thanking Mr Bannon on Twitter. He wrote: "I want to thank Steve Bannon for his service. He came to the campaign during my run against Crooked Hillary Clinton - it was great! Thanks S."
The danger for Mr Trump now is that Mr Bannon could ultimately turn on him.
Joel Pollak, Breitbart's senior-editor-at-large, wrote: "It may turn out to be the beginning of the end for the Trump administration, the moment Donald Trump became Arnold Schwarzenegger,” referring to the former California governor's "re-invention as a liberal".
In his own words | Steve Bannon
Profile | Steve Bannon