Does union canvassing affect voter turnout under conditions of political constraint? Empirical evidence from Illinois

The positive effects of union canvassing on individual-level union member voter turnout within union-friendly environments have been well documented. Yet, whether unions increase turnout among their membership under constrained circumstances has remained unexamined. Furthermore, there is little consensus on whether union canvassing effects are generalizable to populations with heterogeneous political attributes and individual characteristics. This paper identifies the mechanisms that might explain how union canvassing can be effective under conditions characterized by anti-union legislative actions, adversarial judicial decisions, and right-wing populist rhetoric. We use canvassing and turnout data taken from the 2016 Democratic state and Cook County primary election in Illinois, and our results show that, despite constrained political circumstances relative to those found in previous studies, union canvassing achieved positive union membership turnout effects. This study also tests the moderating effects of individual political attributes (ideology and vote propensity) and voter characteristics (income and ethnicity). The most salient finding is that the effects are more potent for ideologically conservative registered Democrat voters, highlighting the imperative of recognizing the ideological heterogeneity among union members and suggesting specific resource allocation strategies under politically constrained conditions.