This past Friday, Donald Trump abruptly reversed course on birtherism, accepting President Barack Obama’s constitutional legitimacy for the White House after he spent five years questioning it.

But what about Trump’s other conspiracy theories?

After all, birtherism is just one wild idea that Trump has had when it comes to Obama. During a media blitz in 2011 ― when he first began to make his birther claims ― Trump also surmised that the president did not write his own memoir. Instead, he insisted, Bill Ayers, the former Weather Underground leader, penned Dreams from My Father.

“Look,” he told Sean Hannity, “he was born ‘Barry Soetero.’ Somewhere along the line, he changed his name. I heard he had terrible marks, and he ends up in Harvard. He wrote a book that was better than Ernest Hemingway, but his second book was written by an average person. ... I say Bill Ayers wrote the book.”

Asked why, Trump continued.

“He was best friends with Bill Ayers,” he explained, and Hannity just let him roll on at that point. “Bill Ayers was a super-genius. And a lot of people have said he wrote the book. Well recently, as you know last week, Bill Ayers came out and said he did write the book. Barack Obama wouldn’t be president ― and, you know, I wrote many best-sellers, and also, No. 1 best-sellers, including The Art of the Deal. So I know something about writing. And I want to tell you, the guy that wrote the first book didn’t write the second book.”

This wasn’t some one-off suggestion, either. Trump was adamant that Ayers wrote the book. He made a similar claim on Laura Ingraham’s radio show and raised doubts about the authorship of the memoir during an interview with Fox News in January 2012. He even tweeted about it in 2013.

WH claims it lied about Pres. Obama living with his uncle b/c “wasn’t mentioned in his book.” I guess Bill Ayers never knew about it! — Donald J. Trump (@realDonaldTrump) December 9, 2013

All of this, of course, was rubbish, though Trump was hardly alone in pushing it. Ayers had been an acquaintance of Obama’s in Chicago. The two had met in the spring of 1995, and Ayers had hosted a coffee for the aspiring local politician later that year. Around that time, Dreams was published. But multiple investigations had concluded that the two had a passing relationship and not much more.

Obama, however, was routinely dogged by the Ayers association during the 2008 campaign. As was Ayers, who occasionally tried to deflect the attention through sarcasm. In one instance, he was asked by a conservative blogger if he had been the ghost writer of Obama’s memoir.

“I said…. ‘Yes, I wrote every word of Dreams from my Father. And if you can help me prove it, I’ll split the royalties with you,’” Ayers recalled in an email to The Huffington Post.

“She was delighted to get the scoop, dutifully blogged it, and the story went viral until Jonah Goldberg, I think, and Bill O’Reilly said I was pulling her leg. Jamie Weinstein, for example, from the Daily Caller, asked me to please tell him the truth about whether I’d written the book, and I responded for the zillionth time, that yes I had, and please split the royalties, and he said several times, ‘No. I know the joke but tell me the truth.’ I repeated the whole thing and he said, ‘I get it, but tell me the truth.’ So there we were: If I said I wrote it, I was mocking the right-wing conspiracy nuts, but if they said I wrote it, that was an example of intrepid investigative reporting. A perfect contradiction.”

This exchange happened in 2009. Trump was continuing to push the conspiracy theory in 2011. His campaign did not return a request for comment on his Ayers theory.

There is a certain irony to Trump accusing Obama of having his memoir ghost-written. In the aforementioned Hannity interview, Trump noted the success of his own book, The Art of the Deal, which is described as part memoir, part business advice. Unlike Dreams, that book was most certainly penned by someone else: a writer named Tony Schwartz, who has become one of Trump’s most vocal critics.

“The only thing Donald Trump knows about writing is that he can’t do it,” Schwartz emailed HuffPost. “That’s why he hires others to write a book. He did not write a single sentence of The Art of the Deal ― not one. He lies about that as he lies about virtually everything.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.