Photo by Zuma Press, Inc./Alamy Live News

Barack Obama looked out at the crowd and did not like the country that looked back. He stood in a high-school gymnasium in Detroit, with skinny arms and a helmet of silver hair, at a recent campaign event for Michigan’s Democratic slate. He was remembering that politics was more dignified when he was president: a time when politicians dealt with their disagreements with reluctant professionalism and a begrudging mutual respect as opposed to the farcical insults thrown around today. America, he said, had lost its way and needed to return to the “old-fashioned virtues of honesty and integrity and kindness and compassion”. It was a plaintive plea. He wanted those at the rally to recognise that the midterm elections on 3 November presented an opportunity to rein in the excesses of Donald Trump’s corruption and demagoguery. But he seemed to want more than just a check on Trump’s marauding will to power.…