The Effect of Simultaneous Proposals: The Case of Immigrant Enfranchisement

Is voting behaviour in referendums impacted by having similar proposals on the same topic? Drawing on the literature on the compromise effect, I argue that support for a proposal is higher if it is presented alongside a more extreme version. Empirically, I apply this argument to the substantive topic of electoral rights for immigrants—a contemporary frontier of democratisation. First, I test the argument with an original survey experiment fielded in the United States. Second, I delve into the practical relevance of the topic by focusing on Swiss immigrant enfranchisement referendums. Two case studies complement a subsequent analysis of voting data. The results of the experiment and the observational analysis both support the idea that the compromise effect shapes voting behaviour in simultaneous referendums. These findings call on scholars to consider the compromise effect in the study of popular votes and political decision-making more generally.