From 1953 to 1972, the SPD’s percentage of valid votes grew from federal election to federal election (“comrade trend”). This was explained by changes of class structure: an increase of white collar employees and civil servants, a slight decrease of manual workers, and big and a large decrease of self-employed. In comparison, the share of Catholics and Protestants, and the religious engagement of the German electorate remained quite stable. The voting behavior of these groups over time is documented, and the “comrade trend” is explained by a political re-orientation of the new middle class. Then, the party system is reconstructed independently from social structure based on scalometer ratings of parties and leading politicians. Finally, stability and change of positions of class and religious groups within the two-dimensional reconstructed party system is shown, supporting the results of the documented frequency tables.