Since change of in the economy has its first impact on people in the labor force, commercial and occupational classes are delineated by status in the labor force and respondents’ own occupation. Cohort and period effects are identified for the impact of occupational classes (manual workers, white collar employees, self-employed, not in the labor force) and union membership on SPD-vote. The hypothesis that unionized workers stay stable SPD-affiliates across generations is falsified, but in each generation the gap towards non-unionized workers remains the same. As expected, white collar employees adjust their voting behavior to that of manual workers and, if they are unionized, to that of unionized manual workers. A cohort analysis for commercial classes shows that the political adjustment of white-collar employees to manual workers is mainly due to routine non-manual administrative, sales and service workers. Collapsing SPD and Green Party to a left party group results in a new cleavage line between left and right, that is between professionals of the younger generations against managers and petit bourgeoisie.