Political parties have two bases of support and legitimacy: voters and members. As regards the number of party members, from a comparative perspective the Netherlands has always performed modestly. And in the first two decades of the twenty-first century, just over 2 per cent of the electorate is a member of one of the many political parties the Dutch multiparty system has to offer. In descriptive or socio-demographic terms (e.g. age, gender, educational level), these members do not reflect the voters of their party. From a substantive perspective, however, party members and voters are much more alike. In ideological left–right terms as well as according to their attitude towards several important old and new political issues (euthanasia, income differences, European integration, integration of ethnic minorities), there is a high congruence between members and voters. Moreover, a decline in party membership for individual parties is not associated with a decrease in socio-demographic similarity nor substantive congruence. Arguably it is primarily the normative shift in the public debate in favour of descriptive representation that fuels the critique on parties as pillars of contemporary representative democracy, not the fact that these parties and their membership no longer substantively represent their electoral support base.