During the last thirty years, the Left’s electoral strength has constantly decreased in most of the advanced democracies. At the same time, the social composition of its electorate has changed considerably, with a substantial loss of votes among the less privileged social groups – first of all, the blue collars. This article focuses on the relationship between these two phenomena and investigates whether the main left-wing parties’ reduced representation of the more disadvantaged groups may have influenced their electoral decline. Our starting point is the change in social stratification that has affected the Western democracies since the 1980s. Then we tried to highlight the relationship between the old and new occupational classes and the...