This dissertation centres on actors who engage in political solidarity, defend collective endeavours and support the rights of people in need. It substantiates that individuals, civil society and institutional actors enact political solidarity. Thus, political solidarity concerns a wide range of actors, practices and dispositions beyond institutional settings. Results evidence that political solidarity is conditioned by people's belonging to different groups, orienting their behaviours and attitudes towards others. Findings point to the importance of contextual factors such as multicultural policies in explaining welfare eligibility attitudes towards migrants, highlighting the role group identity dynamics plays in the allocation of welfare support and caring obligations across groups. Overall, the research concurs with previous studies showing that structural and cultural cleavages shape with whom individuals feel bounded in solidarity. As a result, progressive and inclusive political standings across groups are strongly associated with highly-educated cosmopolitan individuals sharing both left-economic and cultural-libertarian value orientations.