In recent decades, there has been a considerable expansion of citizen participation in protests and voluntary advocacy groups. To analyze this development, the social movement literature and the interest group literature have emerged. Yet these two bodies of literature have not communicated with each other and have rarely incorporated knowledge from other fields in political science. As a result, critical questions remain unanswered regarding the political influence of advocacy groups. How do they affect politicians? To what degree do informal groups use lobbying tactics? Are socioeconomically advantaged groups more influential? This thesis endeavors to address the above shortcomings by bridging the literature on social movements, interest groups and political parties. The purpose of the thesis is to explain if and how advocacy groups affect public policy and to analyze which resources that are required to influence political decisions. The focus is on informal and loosely organized social movement organizations (informal SMOs): parental networks, staff networks, and village networks. To test my arguments, I use a unique database on protests and lobbying against school closures in Sweden. Closures of public schools have been one of the most important drivers of political activism in Sweden. The results are presented in three essays. Essay I tests new electoral mechanisms that could condition the political influence of advocacy groups. The results suggest that the political influence of informal SMOs on school closure decisions varies according to the type of voter they mobilize: swing voters or core voters. Essay II demonstrates how informal SMOs use lobbying tactics, such as presenting policy-relevant information, to influence politicians. Social movement scholars often focus on protests and ignore lobbying tactics. However, the results show that SMOs that present policy-relevant information are more likely to stop school closures than SMOs that mobilize large protests. Essay III analyzes which informal SMOs exchange policy-relevant information with politicians. Previous studies on the use of lobbying tactics have ignored activist resources. My results suggest that SMOs mobilizing high-income activists and activists with analytical and civic skills are more likely to present policy-relevant information. This is problematic given normative ideals of equal access to decision-making by all members of society.

The debate between the Power Resource Approach and the New Politics thesis has been ongoing for decades. The PRA claims that the labor movement continues to be the most prominent defender of the welfare state. The NP-thesis, on the other hand, claim that the welfare state in itself has created new interest groups, clients of specific welfare state programs, that have largely taken over as the most prominent welfare state upholder. In an attempt to empirically evaluate the usefulness of these two theories, quantitative data on protests against cuts in the sickness benefit program in Sweden during the years of 2006-2019 have been collected through investigating newspaper ma- terial. The results show that the protest engagement among client groups is greater than the engagement among the labor movement when looking at protests directed specifi- cally against cuts in the sickness benefit program. This result lends credibility to the NP- thesis while it questions the PRA. When including protest events directed against cuts in the sickness benefit program among other welfare retrenchment related grievances, the results show that the labor movement continues to be a prominent defender of the welfare state. Additionally, the PRA/NP literature is criticized for failing to acknowledge the possibility of protest coalitions between client groups and the labor movement or- ganizations. The results show that coalitions of protest exist, but more research is needed to conclude how coalition building relates to the theoretical debate regarding the welfare state upholders.