"She was confident he would win and was very happy when he did", she said on Wednesday.
It was a blistering attack against the man who helped deliver the presidency to Trump.
Even then, presidential aides might have laid the groundwork to fight the book by quietly raising doubts about Wolff's past work, some of which has been criticized as recreating scenes inaccurately.
Later Wednesday, Trump attorney Charles Harder threatened legal action against Bannon over "disparaging statements and in some cases outright defamatory statements". They sent Wolff and his publisher a cease and desist letter Thursday.
As a gossipy firsthand account of life in the White House, which sections are worthy of a cease-and-desist letter, and which of a full-on investigation?
Alternately, they might have taken the high road and simply declined to comment, letting the media and the public hash out the trustworthiness of the book's version of events.
While the Trump administration is trying to spin the new "no personal device" policy as a security issue, the fact of reporter Michael Wolff's bombshell White House exposé release this week certainly calls that into doubt.
White House spokeswoman Sarah Huckabee Sanders said Mr Bannon's description of Mr Trump Jr as treasonous was "a ridiculous accusation". The meeting has become a focus of federal and congressional investigators. "This is all about money laundering".
"You realize where this is going", Bannon is quoted as saying.
Bannon's main financial backer is formally cutting ties with the former Trump adviser.
Sanders said Bannon and Trump last spoke in the first part of last month. Their path to fucking Trump goes right through [former Trump campaign manager] Paul Manafort, Don Jr. and Jared Kushner.
So far, there is no indication that Bannon is being investigated by special counsel Robert Mueller.
Additionally, Trump "had a longtime fear of being poisoned", Wolff wrote; "one reason why he liked to eat at McDonald's - nobody knew he was coming and the food was safely premade".
The upcoming political book by Wolff describes the on-and-off relationship between Hicks and Lewandowski, which had been a subject of controversy in the White House. Or they could have made key players available for extensive interviews with rival publications to set the record straight on some of the key moments described in the book.
The schism could test whether Mr Trump or Mr Bannon has more resonance with the conservative base that has sustained the President through a tumultuous tenure marked by low poll numbers.
Wolff's explosive exposé of Washington behind closed doors will be released on Friday, January 5 to clamoring crowds, desperate to get their hands on the alleged secrets of the most controversial administration in American history.
Bannon's comments in the book are just his latest published criticism of the president and his family.