Europe has been marked by many profound changes since the 1980s. Among those prominently discussed in the political economy literature are the massive decline in trade union membership, the alarming rise in income inequality, and the increasingly disproportionate distribution of labor market risks. This thesis combines these issues and explores how unionization relates to income and risk inequality by investigating the roles of trade unions and trade union membership in the political arena: One article analyzes if and how unions represent high-risk individuals in the legislative arena by lobbying for labor market outsiders in dualization reforms; three articles examine how union membership shapes electoral demand for policies alleviating income and labor market risk inequality and electoral support for left-wing parties in pursuit of such policies. In doing so, this thesis contributes to our understanding of solidarity in the context of inequality and how union decline might fuel inequality.