Mr Biden says he is standing again to help ordinary Americans and to save democracy from Mr Trump’s vengeful demagoguery. And the former president’s scowling, evasive and truth-defying appearance on the debate stage did nothing to diminish the urgency of those two aims. Yet if Mr Biden really cares about his mission, then his last and greatest public service should be to stand aside for another Democratic nominee. After a lifetime of public service, Mr Biden is befuddled and incoherent too infirm, frankly, to cope with another four years in the world’s hardest job. Should Joe Biden run for presidency again ?