In the summer of 2016, with his campaign lacking a leader, Mr Trump made Mr Bannon - a scruffy, scrappy former businessman who was then the executive chair of Breitbart News, a website preaching white nationalism - the campaign's chief executive.
Steve Bannon is out at SiriusXM, the satellite radio company announced Tuesday, hours after it was revealed Bannon had been booted from Breitbart News. "When he was sacked, he not only lost his job, he lost his mind", Trump said.
Steve Bannon, appointed chief strategist and senior counselor to President-elect Donald Trump arrives arrives for the Presidential Inauguration of Trump in Washington, January 20, 2017.
But he appears to have become increasingly isolated amid reports that he had lost the support of a major financial backer.
He issued a statement Sunday praising the president's eldest son.
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On Monday, Bannon tried to back-pedal from his comments.
Excerpts from the book started surfacing last week and Trump and White House staffers spent most of last week denying most of Wolff's descriptions of an Oval Office in tumoil and a president coming unhinged. The next day on January 4 it was reported that Breitbart stakeholder and billionaire Republican donors the Mercer family pulled their financial support of Bannon. "I'm not saying all of it - particularly the parts about Steve Bannon - but this book should not be taken seriously".
On Tuesday Bannon released a routine statement on the development where he said he's "proud of what the Breitbart team has accomplished in so short a period of time in building out a world-class news platform".
Wolff's book draws a derogatory portrait of Trump as an undisciplined man-child who didn't actually want to win the White House and who spends his evenings eating cheeseburgers in bed, watching television and talking on the telephone to old friends. "They're going to crack Don Junior like an egg on national TV", Wolff quoted Bannon as saying. He added that special counsel Robert Mueller's investigation of ties between the Trump campaign and Russian Federation largely involve money laundering and loans by Deutsche Bank to Trump Jr. "Their path to f****** Trump goes right through Paul Manafort, Don Jnr and Jared Kushner ..."
The Federal Bureau of Investigation, it was also disclosed, will be looking into the Clinton Foundation.
An attorney for the publisher of Michael Wolff's book Fire and Fury says no retraction or apology is coming.