Drawing on data from the twenty year long German Socioeconomic Panel Study, we show that partisanship is bounded. Almost every West German, East German, and immigrant never supports one or both of the major parties and most people vary support for their party by claiming no partisan preference. Hardly anyone ever selects each of the parties at different points in time. Immediate social networks join with social class and religious factors to structure partisanship. The same social logic underpins partisan choice among West Germans, East Germans, and immigrants, though factors unique to each population are also present.