Joe Biden was never going to win. ‘Are you forgetting what you said two minutes ago?” That was the question Julián Castro addressed to his opponent Joe Biden during the Democratic presidential primary debate in September 2019. After the debate, Castro was backed up by fellow candidate Cory Booker, who wondered aloud whether the 77-year-old Biden had the vitality to be elected in 2020. “I think that we are at a tough point right now because there’s a lot of people who are concerned...