Ronald Reagan showed early signs of Alzheimer's while still in office, according to an excerpt from an upcoming book written by one of his sons.
The son of the Republican president, recounts in the book "My Father at 100, a Memoir" that he suspected there was something wrong three years into Reagan's first term.
According to Reuters, Ron Reagan says that watching his father debate Democratic presidential nominee Walter Mondale felt like a bad dream was being realised.
"My heart sank as he floundered his way through his responses, fumbling with his notes, uncharacteristically lost for words. He looked tired and bewildered," he continues, reports the news source.
This has caused controversy between liberal broadcaster Ron Reagan and his half brother conservative Michael Reagan, who claims he has sold out his father and needs praying for.
"Ron, my brother was an embarrassment to his father when he was alive and today he became an embarrassment to his mother," he tweeted.