40 years ago, Ronald Reagan shrugged off the fears about age that Joe Biden faces now

As Joe Biden faces George Stephanopoulos, Laurie Kellman recalls how Ronald Reagan swatted away the age issue with witty ripostes and a remarkable recovery after he was shot at the age of 70

Ahead of Friday's interview with George Stephanopoulos on ABC News, the verdict on Joe Biden's performance in the CNN debate on June 27 was that it was a disaster for the US president.  Picture: Justin Sullivan/Getty 

The age question for US presidential candidates is more than four decades old. Former president Ronald Reagan answered it with a pledge to resign if he became impaired, and later with a clever joke that reset his campaign from a stumbling debate performance to a 49-state landslide and a second term.

“I will not make age an issue of this campaign,” Reagan said to the question he knew was coming, in perhaps the most famous mic-drop moment in campaign history.