Unions as mobilizing institutions in the U.S., 1964-2000

This paper examines how unions affect turnout and assesses the consequences of the dramatic decline in union strength since 1964 for the composition of the U.S. electorate. Our analysis relies on individual-level data from 1964 through 2000. We first estimate individual-level models to test for the independent effects of union membership and union strength on individuals’ probabilities of voting. We then estimate more complex individual- level models to examine whether or not the effect of individual union membership and overall union strength varies across income levels. We find that unions increase turnout by increasing turnout of union members as well as turnout of non-members. And we find that the effects of union mobilization are approximately equal for the bottom two thirds of the income distribution, but are significantly less for the top third of the income distribution. By simulating what turnout would be were union membership at its 1964 level, we show that the decline in union membership since 1964 has had substantial implications for class-bias in the electorate, as well as for the overall level of turnout.