This paper investigates the dynamics of voter defection and party switching in Western Europe in the context of the growing popularity of Eurosceptic Political parties. Using data from the European Social Survey on previous voting behavior and present proximity to present political parties, it explores those segments of the electorate which (in contrast to past ballot behavior) express a proximity to Eurosceptic political parties. Those voters expressing proximity and preference for different political parties from the ones they voted for previously are compared and explored from socio-economic, policy preference, and value structure points of view. Moreover, it is explored which voters of which mainstream parties defect for which types Eurosceptic parties (hard Eurosceptic/soft Eurosceptic and left-wing/right-wing). As such, the paper not only contributes to our insights into party-voter dynamics but also touches upon the field of party-competition. It is assumed that there is not one diffuse mass of discontent voters that vote for Euroceptic fringe parties randomly, but that there are differences between the constituencies that are likely to take their vote to far right or far left Euroseptic candidates. It thus seeks to identify the most vulnerable constituencies of various moderate, pro-European parties, as well as the most likely political destinations of such voters.
