Donald Trump's biographer said he believes the former president's cognitive capabilities are failing because of his age.
Tim O'Brien, journalist and author of TrumpNation, said he noticed that Trump was not "cognitively together" before the book was released in 2005.
"I flew around with him in his plane and walked his golf courses with him 20 years ago... Not very cognitively together then," O'Brien said on X, formerly Twitter. "Much less cognitively better now."
The former New York Times journalist was responding to Trump saying at a campaign event in Portsmouth, New Hampshire, that his cognitive health is even better than it used to be. Trump is the front-runner for the 2024 Republican presidential nomination.
Former President Donald Trump speaks at a press conference at 40 Wall Street on January 17, 2024, in New York City. Trump's biographer said he believes Trump's cognitive capabilities are failing because of his age. Alexi J. Rosenfeld/Getty Images
O'Brien is a known critic of Trump with Democratic leanings and was a campaign adviser for Michael Bloomberg during his presidential campaign in 2020.
"I think, cognitively I'm better than I was 20 years ago," Trump told supporters Wednesday. "I don't know why."
Trump also said he feels like he is "about 35 years old."
Trump and O'Brien were involved in a legal dispute over the book after the author wrote that the 45th president was worth between $150 million and $250 million. Trump said he was a billionaire and sued, but the case was thrown out by a judge in 2009.
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Despite a number of reports of Trump's so-called "cognitive decline," there has not been any proof to back up the claims. Anti-Trump accounts on social media and partisan personalities have used Trump's and President Joe Biden's ages, 77 and 81, respectively, to question their health and capabilities.
Trump insists he is healthy and shared a report he said was from his physician in November. The report said his his cognitive health is "exceptional."
Previously, Trump's former director of strategic communications, Alyssa Farah Griffin, told CNN's State of the Union in December that her former boss was "slowing down."
Griffin has been critical of Trump since she resigned from his White House in December 2020.
"It's kind of remarkable," she said. "I've been watching the clips from Trump's visit to Iowa and I'm stunned having spent a lot of time with him in 2020 and years before—he is slowing down."
In response, Trump campaign spokesperson Steven Cheung told Newsweek that "Alyssa Griffin is slowing down and she needs to get it checked out."