After years of decline, the once almighty mainstream parties have reached an unprecedented electoral low in Western Europe. This raises concerns about government manageability and the overall stability of representative democracies. I aim to investigate how social groups can play a pivotal role in reversing this trend. Specifically, I will explore how mainstream parties can effectively attract diverse social groups and as such expand their electorate through strategic combinations of policy and social group appeals. Social group appeals are defined as statements that mention an association or dissociation with a social group (such as farmers, the poor, …). Policy appeals are statements that indicate whether the party is in favor or against a policy. The project comprises four main parts. Firstly, I will construct a new dataset using a pioneering supervised learning approach and explore variation in the social group appeals used by 29 mainstream parties in eight West-European countries from 1960 to 2023. Secondly, I will analyze the variation in programmatic preferences among the social groups most targeted by mainstream parties across the same eight countries, using secondary data from the European Social Survey. The third and fourth components of the project test the effectiveness of social group and policy appeals within a multidimensional framework. This will be accomplished through a survey and conjoint experiment in Flanders, encompassing eight distinct social groups.