When trying to understand political change in democracies it is natural to think of voters as the driving force. But much political change—including the elections of Donald Trump and Boris Johnson—is as much a product of dynamics happening within existing parties—

enabling such candidates to come close to power—as it is a product of voters voting for those parties. A complete understanding of political change thus requires understanding the behavior and role not only of voters, but also of parties.

This thesis studies political change and the roles of voters and parties in driving such change. In the first chapter I study the political consequences across and within parties of refugee migration. I combine Danish administrative data on local politicians from 1993-2013 with quasi-random refugee placements to show that refugee migration does not increase voters’ support for the far right. Instead, it increases the propensity for candidates from lower social backgrounds to be elected. This effect is driven both by parties and voters: First, parties place candidates from lower social backgrounds higher on lists and switch to a party system, where individual candidate popularity, rather than party list position, determines election. Second, voters cast individual votes for these candidates from lower social backgrounds. In a nationally representative survey experiment I show that voters’ preference for candidates from lower social backgrounds can in part be explained by refugee migration increasing their preferences for redistribution towards natives, preferences that are mirrored by candidates from lower social backgrounds.

In the second chapter of my thesis, I further explore the role of parties in responding to and driving political change. Specifically, I derive a theoretical framework to study how changes in the ideological bias favoring a party affect the propensity to run an open list, and how this in turn affects their support from voters. I find that parties run closed lists if the ideological bias is small. However, when voters become sufficiently biased towards one party, that party opens up its list. This switch to open lists in turn increases their support from voters beyond the effect of the ideological bias. The reason for this is that candidates in popular parties exert more effort in open than closed lists. These results imply that large parties are more powerful in proportional representation systems where parties can choose their list structure compared to closed list systems.

Overall, this dissertation shows that when trying to understand political change, it is important to consider the role not only of voters, but also of parties in driving such change.