Based on a survey of members of AFL-CIO-affiliated unions in Pennsylvania, this paper investigates the influence of unions on how their members voted in the 1984 Presidential election. The authors find that unions had little effect on the number of members who voted but surprisingly strong influence on the Presidential choice of those who did vote. Union members who actively participated in their union, held union leadership positions, and reported that they had received literature or telephone calls about the election from their union were significantly more likely than other members to support the candidate endorsed by their union (Mondale). The electronic media influenced voting behavior significantly, but traditional forms of union communication were more influential than many believe.