This article examines early childhood antecedents of adults' political orientation. Using longitudinal data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, we investigate associations between parenting beliefs and behaviors, child temperament, and attachment security during early childhood in relation to adult political ideology and party affiliation at age 26 years (N = 1,364). Young children's fearful temperament and anxious attachment security, as well as mothers' authoritarian parenting beliefs in early childhood, predicted conservative political orientations at age 26. Children's abilities to focus attention and avoidant attachment security predicted liberal orientations. These findings provide evidence that multiple aspects of early developmental experience-temperament, parenting, and infant-mother attachment-are associated with later political orientations. (PsycInfo Database Record (c) 2020 APA, all rights reserved).