Joe Bidens presidential debate behaviour not a one-off, says Watergate reporter Carl Bernstein [Video]

Veteran Washington journalist Carl Bernstein says those “very close” to Joe Biden have told him the “horror show” debate performance was not a one-off and that the US president’s cognitive decline has accelerated since the start of the year.

Biden’s halting and sometimes befuddled performance in last week’s debate has fanned concerns about his age and sparked criticism from donors, voters and some Democrats.

While some critics have pointed fingers at Biden aides who prepared him for the debate, others including The New York Times’ editorial board said Biden should step aside as the Democratic Party candidate against Donald Trump in the November 5 election. Biden and top Democrats say he has no plans to do so and intends to beat Trump.

Bernstein, the former Washington Post investigative reporter who rose to fame for his reporting on the Watergate scandal that …