It has been commonly assumed that post-adolescent youth have fewer political discussions with parents than doadolescents, due to transitional events in young adulthood and the emergence of new age-appropriate socializingagents, like peers, colleagues, and romantic partners. We proposed a contrasting view that post-adolescent youthhave more frequent political discussions with parents due to their increased political interest over time. Using anaccelerated longitudinal design (n=4286), we found that neither transitional events nor political discussionswith other socializing agents decreased political discussions with parents. The long-term developmental trajectoriesfor political discussions with parents and youth's own political interest showed a linear increase fromadolescence to young adulthood. Cross-lagged models showed that youth's political interest positively predictedpolitical discussions with parents over time and vice-versa. These findings indicate a need to see political discussionswith parents as a parent-youth bidirectional process.