Richmond crowd reportedly went silent as 77-year-old mixed up the president and ex-president for third time in past six months
Donald Trump confused Barack Obama for Joe Biden at a rally in Virginia on Saturday, triggering further questions about the age of the likely Republican presidential nominee who has made a string of such gaffes.
It also comes at a time of similar concerns about the Biden. At 77 and 81 respectively, Trump and Biden are the oldest people to run for the presidency in US history.
