Teaching an undergraduate class on democracy at Princeton University’s School of Public and International Affairs this semester has felt urgent and clarifying. In the classroom, we’ve been looking at backsliding and the slow corrosion of democratic norms in so-called democratic countries. Meanwhile, what’s been happening outside the classroom in more than 120 universities around the US and the world tells us a more ominous story about democracy. For two weeks, we focused on the United States; there were lively discussions on political polarization, January 6 and the threat posed by supporters of Donald Trump, as well as how robust or...