Jon Stewart and 'Pod Save America' hosts raise concerns about Biden's mental health following 'Original Sin' book, highlighting issues of transparency.

Many Americans have been thinking about former President Joe Biden's health in recent weeks — but it was his mental agility that concerned them. After Sunday's announcement that Biden has been diagnosed with Stage 4 prostate cancer,

In a copy of “Original Sin” obtained by ABC News, journalists Jake Tapper and Alex Thompson allege Joe Biden hid info about his son Beau's cancer diagnosis.

A look at the times former White House press secretary Karine Jean-Pierre denied former President Joe Biden was in declining mental or physical health.

Biden's health, both physical and mental, was discussed at length during the 2024 presidential election cycle, more recently after excerpts from a new book by CNN 's Jake Tapper and Axios' Alex Thompson, Original Sin: President Biden's Decline, Its Cover-Up, and His Disastrous Choice to Run Again, were published by multiple media outlets.

Megyn Kelly hosts a struggle session for CNN anchor Jake Tapper over the way he has now published a book about President Biden's mental decline after rarely mentioning it on his daily television show for four years.

Former President Joe Biden's aides privately discussed the possibility of the president needing to use a wheelchair if he were re-elected.

Democratic presidential hopefuls for 2028 are scrambling to clean up comments defending former President Joe Biden’s evident cognitive decline during his 2024 reelection bid. New details are emerging about the extent of Biden’s failing mental acuity in office and the coordinated effort to conceal his decline.

The CNN host extended the olive branch during an interview with Megyn Kelly. Tapper, whose new book "Original Sin" dives into an alleged cover-up of Biden's declining health inside the White House, said that Trump was keyed into something he wasn't.