Moving the Unmoved Mover?: The Origins and Limitations of Systematic Individual-Level Change in Party Identification∗

Political scientists have long disagreed about the nature of individual-level change in party identification (PID). While some scholars conclude that PID is a stable identity—attributing changes in individual responses to measurement error—others show that aggregate PID responds systematically to short-term forces such as presidential approval. In this article, we use a unique long-term panel measuring PID twelve times in the 2011-2013 period to support a subtle compromise between these competing claims. We show that individual-level PID changes systematically over time even after accounting for measurement error and that this change is related to short-term evaluations of the parties and the president. However, although such change exists, it is modest in the medium term and more common among specific subsets of respondents. We believe that our analysis provides the most systematic examination to date of individual-level changes in PID