There are those who believe that at 80, Joe Biden is too old to serve a second term as president. Yet few clamour for him to hand over to the person who would normally be the heir apparent.
Two years in, Kamala Harris, the first woman of colour to be vice-president, has had her ups and downs. Her relationship with Biden appears strong and she has found her voice as a defender of abortion rights. But her office has suffered upheaval and her media appearances have failed to impress.
