Joe Biden says he’d step down as presidential candidate if a ‘medical condition emerged’

US president Joe Biden has said he would end his presidential campaign if it emerged that he had a ‘medical condition’. Biden’s remarks came amid growing concern about his fitness to hold office, brought into sharp focus after a sluggish debate performance against Donald Trump on CNN. Defending his candidacy, Biden said his age gave him added wisdom and he had a lot left to do, so he was ‘reluctant to walk away from that’.