Identity is present in politics in the way gravity, evolution, or cognition is present in politics; that is to say, it is omnipresent in politics, because it is omnipresent in us. There is no way to read the literature on how humans form and protect their personal and group identities—literature I will survey in this book—and believe any of us is immune. It runs so deep in our psyches, is activated so easily by even weak cues and distant threats, that it is impossible to speak seriously about how we engage with one another without discussing how our identities shape that engagement.
