One generation has dominated American politics for over 30 years

When Barack Obama became president in 2009, it appeared not just to be a changing of the guard, but the end of an era. Men born in the 1940s had occupied the White House for the previous 16 years; now it was the turn of a new generation. Mr Obama was born in the 1960s. His watchwords were “hope” and “change”. He had complained, in one of his many memoirs, about the “arrested development” of American politics, stuck in the “psychodrama of the Baby Boom generation”. It was time to move on, he wrote, from the stale feuds initiated on the college campuses of the 1960s.