Where is the party? Explaining positions on same-sex marriage in Europe among would-be members of parliament

The rapid adoption of marriage equality legislation for non-heterosexual individuals in Europe is attributed to many factors, including dramatic shifts in public opinion, the work of transnational activists and changing international norms. Usually, these factors must be filtered through the halls of parliaments where most policy change happens. Given the importance of parliamentarians’ attitudes, it is surprising that we know so little about how attitudes towards same-sex marriage are distributed across political candidates in Europe and what factors shape them. This article fills that gap by using an underutilised dataset on the political preferences of candidates for parliamentary office. We find that beyond attachment to party families, a candidate’s religiosity and practice has a greater effect on a would-be Member of Parliament’s attitudes towards same-sex marriage. The findings suggest that the success of parliamentary action on lesbian, gay, bisexual and transgender rights depends not on the partisan composition of the legislature, but rather on the representation of secular candidates.