Choices and Changes is the most comprehensive examination to date of the impact of interest groups on recent American electoral politics. Richly informed, theoretically and empirically, it is the first book to explain the emergence of aggressive interest-group electioneering tactics in the mid-1990s–including soft money contributions, issue ads, and 527s (IRS-classified political organizations). Michael Franz argues that changing political and legal contexts have clearly influenced the behaviour of interest groups. To support his argument, he tracks in detail the evolution of campaign finance laws since the 1970s, examines all soft money contributions–nearly $1 billion in total–to parties by interest groups from 1991 to 2002, and analyzes political action committee (PAC) contributions to candidates and parties from 1983 to 2002. He also draws on his own interviews with campaign finance leaders. Based on this rigorous data analysis and a formidable knowledge of its subject, Choices and Changes substantially advances our understanding of the significance of interest groups in U.S. politics.