In this contribution we investigate the claim that Third Way social democratic parties have become new middle class parties with a focus on social investment-oriented socio-cultural (semi-)professionals, while traditional mass social democratic parties focus on a social consumption-oriented industrial working class. Belgium is a strategic research site to test this claim: the Flemish social democrats sp.a are a case for the modern Third Way social democratic party, the francophone social democrats PS for a traditional social democratic mass party. Our innovative approach uses both social classes (a shortened Oesch scale) and social policy profiles – the latter derived from a Latent Class Analysis – in order to analyze both class and social policy coalitions among the electorate. Our results from multinomial logistic regression analyses show that both the sp.a and PS are predominantly working class parties with the strongest appeal among those with as socialist social policy profile, although the PS has a broader welfare support coalition in terms of cross-class appeal and different social policy profiles. Somewhat controversially, we conclude that in the current era of electoral setback, modern Third Way social democratic parties in PR systems risk falling back on a core electorate of socialist working class insiders. We discuss whether the link between social investment-oriented socio-cultural professionals and (Third Way) social democracy in the literature may be exaggerated, or if the Flemish sp.a is a peculiar case in Western Europe. We also discuss how the francophone PS has remained highly successful as a patronage-based party and its implications for working class politics in a wider sense.
