Over time, Bannon’s influence waned over rising tensions with the president, and his association with controversial figures like former Breitbart editor Milo Yiannopoulos, fired after video emerged of comments he made seeming to endorse pedophilia, and Roy Moore, the Alabama Republican who lost a Senate race after being accused of preying on teenage girls.

During Bannon's tenure, Breitbart had become increasingly devoted to promoting him, welcoming him back as a "populist hero" after he returned following his ouster from the White House. Bannon left the White House in August 2017, in the aftermath of the white nationalist rally in Charlottesville, and after giving an unfettered interview bashing colleagues to the liberal American Prospect.

In a statement on Tuesday, Sirius XM announced that Bannon would no longer host Breitbart's radio show: "Breitbart News has decided to end its relationship with Stephen K. Bannon, therefore he will no longer host on SiriusXM since our programming agreement is with Breitbart News.”

Bannon’s position leading Breitbart became untenable after the release of Wolff’s book Fire and Fury, an inside-the-White-House tell-all in which Bannon was evidently a key source and which features him making a number of harsh comments about Trump’s family. The most controversial of these was Bannon’s comment to Wolff that Donald Trump Jr.’s meeting with a Kremlin-connected Russian lawyer at Trump Tower in 2016, in which Trump Jr. sought damaging information on Trump’s Democratic rival Hillary Clinton, was “treasonous.” Federal investigators are currently trying to determine whether the Trump campaign aided what U.S. intelligence agencies have described as an effort to boost Trump’s candidacy in the 2016 election.

Bannon’s comments enraged Trump, with whom Bannon had occasionally spoken after Bannon was forced out of the White House in August. In a statement last week, Trump said Bannon had “lost his mind” and accused him of being a leaker.

Though Bannon’s circle pushed him to release a statement smoothing over the incident last week, Trump’s came out first, making Bannon’s position in Trumpworld clear. Then, in a rare public statement, Bannon’s wealthy conservative patron Rebekah Mercer said she was cutting ties with him and that her family was no longer supporting his political projects. Mercer had been unhappy with Bannon for some time; according to a source with direct knowledge of her comments, Mercer told people over six weeks ago that she was finished with Bannon.

Breitbart’s board, meanwhile, reportedly debated firing Bannon. According to disclosures the company made while trying to obtain congressional press credentials last year, Breitbart is owned by Solov, company founder Andrew Breitbart’s widow Susie, and the Mercer family with a minority stake.