The most important questions in the study of class voting during the last few decades have been whether, to what degree, and why class voting has been declining. Usually, a dichotomous left-right party choice variable has been utilized. This may have distorted de-alignment and realignment, as the rise of the New Left and the New Right has changed the relationship between the social classes and the political parties. In this thesis, we utilize a party family dependent variable on contemporary data instead. We first describe the class basis in 18 West-European countries for all the party families, showing that the party families normally grouped into the Left and Right categories indeed have quite different class bases. The strength of class voting also varies by party family. We then test one of the mechanisms connecting class to voting, namely the role of value orientations. This means that we see how much of the bivariate association between class and voting that disappears when controlling for these intermediate variables. What we find is compelling evidence of the need for a more nuanced party choice variable: The amount of class voting accounted for by the value orientations varies between the party families. The thesis thus i) describes the class basis of the West-European party families; ii) tests a mechanism through which class has its effects on voting; iii) proves the need for a more nuanced, 4th generation dependent variable.