Over the past half century, scholars have utilized a variety of theoretical and methodological approaches to study the attachment or identification voters have with political parties. However, models of partisan (in)stability ignore its bounded character. Making use of Mixed Latent Markov Models, we measure the change and stability of individual-level West German partisan identification captured over a 24-year period via the German Socio-Economic Panel (GSEOP). Results suggest that distinctive subpopulations exist that follow different patterns of partisan stability. One party’s loss is not necessarily another party’s gain.