After documenting the long decline in private sector unionism over the last 50 years, we examine data on NLRB representation elections to determine if changes in the administration of the NLRA during the 1980s reduced the level of organizing activity and success. While organizing activity sharply declined in 1981 (just before President Reagan’s showdown with the air traffic controllers’ union, PATCO), we find little evidence that the changes in the administration of the NLRA later in the decade adversely affected the level of union organizing activity. We then present an accounting framework that decomposes the sharp decline in the private-sector union membership rate into components due to 1) differential growth rates in employment between the union and nonunion sectors, and 2) changes in the union new organization rate (through NLRB-supervised representation elections). We find that most of the decline in the union membership rate is due to differential employment growth rates and that changes in union organizing activity had relatively little effect. Given that the differential employment growth rates are due largely to broader market and regulatory forces, we conclude that the prospects are dim for a reversal of the downward spiral of labor unions based on increased organizing activity.