America’s political binary — left and right, Democrat and Republican — can feel inescapable. But historically, it’s a relatively new development, and academically, some political scientists argue it’s nonsense: What we think of as immutable political realities are instead artificial alliances of political convenience. In this month’s Highlight cover story, senior correspondent Eric Levitz breaks down the case against “progressivism” and “conservatism” and gets at the heart of our partisan divides. Also in this issue: Catholic opposition to Trump. The ethics of surrogacy. And fighting to banish the flu.