The author compared American conversation about race to badminton because he suggested that conversation of race has went from being a taboo subject that no one wants to bring up in fear of causing trouble, to something that anyone could simply talk about on a daily basis. Like badminton, its something that no can get seriously hurt from and consists of two people tossing something back and forth with no negative consequences.
How do the authors use historical evidence to support their claim in this passage? They use primary-source quotations to show that enslaved people in Saint Domingue were willing to destroy property to gain their freedom.