Using the Reinforcing Spirals Model as a framework, this study employed an intensive longitudinal design to explore the effects of partisan media use and discussion on variability and change in partisan identity. Findings suggest that in-party communication promotes stability by reducing variability in identity strength, while also contributing to the strengthening of identity. Identity exhibited a tendency to decay among the strongly identified, absent other influences. Non-affirming communication, in contrast, was associated with increased variability.