‘Take it to the bank -- he said this’: Here's proof that Bannon’s anti-Trump quotes are real

President Donald Trump has dismissed an explosive new book about his administration as "phony," but the author visited the White House at least 20 times and recorded conversations with staffers.

Jonathan Swan, a national political correspondent for Axios, appeared Thursday on "Morning Joe," where he explained the website's reporting on author Michael Wolff's research for Fire and Fury: Inside the Trump White House.

Wolff spent hours at a time in private areas of the West Wing, according to Axios, where he recorded dozens of hours of tapes with a variety of sources, and hosted a dinner for six that included White House strategist Steve Bannon and former Fox News chief Roger Ailes, whose conversations are quoted at length in the book.

Bannon also served as a major source for Wolff, and many of the Breitbart News chief's fans and allies are questioning why he would turn on Trump.

"It is a question that people close to him can't understand, and I think it's incredibly stupid," Swan told MSNBC. "It's something he has been saying privately by the way -- none of this is stuff he wasn't saying privately for months. The new thing is he said it on the record."

Swan offered an anecdote that he said explained Bannon's mindset.

"One little wrinkle I would add, which sort of helps you understand Bannon's psychology and how he thinks about himself, Bannon has told more than one person close to him that if Trump is impeached, he will run in a Republican primary in 2020 against Mike Pence," Swan said. "He thinks he could get more support among evangelicals than Pence. This sounds crazy, (but) it is true. Bannon denies it, (but) I am telling from you my own reporting, multiple sources, take it to the bank -- he has said this."

Swan was dismissive that Bannon's participation in the book was part of some broader political strategy that would one day make sense.

"I think it's reasonable, the idea that there is, like, some four-dimensional chess going on here and Bannon has an end game that none of us aware of -- he's thinking five moves ahead," Swan said. "I mean, give me a break. Give me a break."