 as the party's candidate in November's election. There have been questions about whether 81-year-old Mr Biden has the mental and physical stamina to serve a second term, but this was brought into sharp focus during that 90-minute debate, which was marked by Mr Trump making a string of false or misleading claims and President Biden sounding hoarse for much of the time and sometimes staring and looking confused. The White House later said he had a cold and a sore throat.