Societal divisions and even violence can occur when electoral candidates appeal to race, religion, or tribe. Why do candidates make these ethnic appeals? More specifically, why do some candidates appeal to their own ethnic group while others reach out to other ethnic groups or abandon ethnic appeals altogether? To answer this question, Colm A. Fox adopted a ground-breaking, novel approach to study campaign appeals made by thousands of candidates. He collected and systematically analyzed photographs of over 25,000 election posters from campaigns across Indonesia, along with newspaper reports and interview data. The book shows how electoral rules, political party ideology, ethnic demographics, and social norms shape candidates’ decisions to bond with co-ethnics, bridge across other ethnic groups, or bypass ethnicity entirely. Its findings yield not only insights as to which ethnic identities are likely to become politicized, but also prescriptions on how to curb divisive ethnic politics.