Joe Biden is in a “steep cognitive decline”, according to US Senator Roger Marshall. Marshall, who has a medical background as a physician, told GBN America there is one key giveaway which the 81-year-old often displays in his behaviour. Biden is under pressure to walk away from the presidential race after a series of blunders, the latest coming at a Nato summit where he mistakenly referred to Volodymyr Zelensky as ‘President Putin’. “He’s in steep cognitive decline”, he told Steven Edginton. “I am a physician. The way he walks last fall compared to today is a drastic change. “He walked heel-t…