Jake Tapper on Joe Biden’s decline: Who knew what, and when?

Read time: 6 mins

In brief…

• Jake Tapper tells Lewis Goodall about the moment he realised, during the 2024 debate, that something wasn’t right with President Joe Biden and his health.
• In researching and co-writing his new book, Tapper reveals senior members of the Democratic Party described there being “two Bidens” – one functional, one not – with the latter becoming increasingly present.
• He says that speculation over his health in the US conservative press was largely accurate, but credits the US population for their early skepticism over Biden’s health, stemming from personal experience with aging relatives.

The world gasped in collective shock and sadness during the June 2024 presidential debate between Joe Biden and Donald Trump.

Biden, once a powerful and decisive speaker, appeared frail and confused, confirming months of speculation about his failing health and lack of capability to lead America for a second term.

And perhaps no one was more shocked than Jake Tapper who, alongside his CNN co-host Dana Bash, was hosting the live clash of the Democratic Party and Republican nominees.

"We had iPads so we could communicate with the control room during the debate, and during that 'we finally beat Medicare' moment, I wrote 'holy smokes' because I was just stunned, shocked," Tapper tells Lewis Goodall on The News Agents.

"I didn't know who was in the control room. I wanted to keep it clean, but I obviously had an earthier saying in mind.

"I don't think it's hyperbole to say this is the worst performance in a presidential debate ever – there's nothing even close."

Tapper is an award-winning journalist with more than two decades of reporting and presenting experience, but it was the Biden/Trump debate which has shaped the past 12 months of his career, during which time he has co-written and published his new book, Original Sin, (alongside journalist Alex Thompson) which charts Biden's declining health, and looks into who knew what, and when.

"I wanted to know much more about how long he had been showing signs of being like this," Tapper says.

"Obviously, he wasn't like that all the time, but it was also obvious that was not the first time he had acted like that."

He says aides to the president described the situation as being "almost two Bidens".

"There was the one that you saw on the stump in 2020 that was fine. And then there was this non-functioning Biden, which we all saw the night of the debate, losing his train of thought, not able to come up with the names of top aides or friends – a debilitated adult.

"What happened was, according to our reporting, is that as time went on that non-functioning Biden would rear his head more and more. As all of us who have aging relatives know, it's usually just not like one straight line of deterioration.

"There are good days and bad days, and that's what people saw."

Who knew what about Biden’s health?

Biden eventually stepped down as the Democratic nominee in late July 2024, with Vice President Kamala Harris taking his place in early August.

But during that unusually swift process in US politics (as finding a presidential nominee usually takes months, and requires several rounds of a selection process), questions began being asked about how long Biden's administration, and the Democratic Party more widely, had known about his failing health.

"It's true that conservative media was accurately making the larger argument that there was much more going on behind the scenes," Tapper says.

"Not everything they said was true and not every incident was as described, but their argument was accurate and their larger skepticism was the right one."

Additionally, he says, suspicions about his health grew among the US population – not only because of media speculation, but because of lived experience of aging, and living with aging relatives.

"My dad is 85, my mom is 82 and they are aging at different rates," Tapper says.

"This is one of the reasons, I think, why the American people were so ahead of this story, beyond where the media and Democrats were, because they all understood this.

"They might not understand the intricacies of tariff policy or Brexit, but they understand what it means to be an 82-year-old man who has good days and bad days. They've seen it in their grandparents, their parents, and in themselves."

Some have suggested that Harris should have been the one to raise concerns about Biden's health, being the vice president at the time, but Tapper says she was neither one of his top aides or a confidant of the president.

He believes she would only see Biden in the Oval Office or the Situation Room, during the most important events, when he may have acted sharper than at other times.

Inside The White House, Tapper adds, she was referred to as a "work in progress", in terms of her political position.

Why didn’t the Democrats act?

Tapper says it is "chilling" to know that by the end of his presidency, Biden was not a functioning president, and unable to deal with the national security issues the job entails.

He adds the problem with the US politics, unlike the UK, is that it lacks a system where there is always someone, or multiple someones, waiting in the wings to take over if the country's leader is unable to continue in the job.

The US has the 25th Amendment in its constitution, which can be invoked when a president is no longer capable, but this did not happen.

"Democrats were talking about the 25th Amendment all the time during the Trump presidency because of discussion of how erratic he was with his cabinet, but when it came to the Biden presidency, they weren't really talking about it at all," he says.

"What started out as a nod to his age became something of a cover up, because at a certain point it became a deliberate effort to ensconce him, to sequester him away from people."

At the time, however, top Democrats were telling the public that Biden was in good health, but simply working behind the scenes. Tapper says even they weren't seeing the president at that time.

Tapper believes Biden’s personal issues affected his decline

Biden suffered a number of personal tragedies during his life – the deaths of his first wife Neilia Hunter Biden and daughter Naomi in a car crash in 1972, and lost son Beau to an aggressive form of brain cancer in 2015.

But it was the legal case against his son Hunter, which began in 2020, which Tapper says dropped a "psychic weight" on the president when he was found guilty on drug and gun charges in early June 2024.

"He was afraid he was going to lose Hunter," Tapper says.

"Hunter was talking about how the Republicans were trying to get him to relapse.

"That weight, that fear of losing his third child, really weighed on him, and aides say that caused a great deal of the deterioration."

Conspiracy theories emerge surrounding Biden’s cancer diagnosis

More recently, Biden has revealed more of his own personal health struggles, confirming he had been diagnosed with Stage 4 prostate cancer in May 2025.

This sparked new conspiracy theories, with some claiming this may also have been concealed during the 2024 election campaign, but Tapper says there is no evidence to suggest this is the case.

"I understand the skepticism people are expressing when it comes to questions about the timing of this Biden announcement," Tapper says.

"I just don't know that it's anything other than what it's presented as."

America has a history of presidents hiding health issues from the public, including Woodrow Wilson suffering a stroke, Franklin Roosevelt having polio, John F Kennedy having Addison's disease and Ronald Reagan's Alzheimer's.

"Presidents not being transparent about their health is as American as apple pie,"  he adds.

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