Opinion Formation and Change in Referendum Campaigns

Abstract

The referendums on the European Constitutional Treaty which took place in Spain, France, the Netherlands and Luxembourg in 2005 provided scholars with a unique opportunity to examine more closely the process by which voters form and change opinions on complex and unfamiliar political questions. Only a few voters in these instances came to the referendums on the European Constitution with strongly held and fully formed opinions regarding the issue(s) involved. This is largely because constitutional matters tend, under most circumstances, to be the exclusive preserve of political elites. When they are introduced into the realm of mass electoral politics, voters must begin a complex learning process in order to become familiar with the underlying arguments and issues. We know from the study of referendums at other times and in other places that this process of opinion formation is complex and highly uncertain, depending on the issues involved (Zaller, 1991, 1992; LeDuc and Svensson, 2002). According to a special Eurobarometer published in January 2005, only 11 per cent of respondents indicated that they knew much about the contents of the Constitutional Treaty.1 About a third of those surveyed reported that they had not heard of the treaty at all, while the balance (56 per cent) said that they had heard something about it but knew very little about its substance. Referendums on issues such as these with which the mass public is largely unfamiliar often tend to be highly volatile and therefore unpredictable events.