Organized interests do not have direct control over the fate of their policy agendas in Congress. They cannot introduce bills, vote on legislation, or serve on House committees. If organized interests want to achieve virtually any of their legislative goals they must rely on and work through members of Congress. As an interest group seeks to move its policy agenda forward in Congress, then, one of the most important challenges it faces is the recruitment of effective legislative allies. Legislative allies are members of Congress who “share the same policy objective as the group” and who use their limited time and resources to advocate for the group’s policy needs (Hall and Deardorff 2006, 76). For all the financial resources that a group can bring to bear as it competes with other interests to win policy outcomes, it will be ineffective without the help of members of Congress that are willing to expend their time and effort to advocate for its policy positions (Bauer, Pool, and Dexter 1965; Baumgartner and Leech 1998b; Hall and Wayman 1990; Hall and Deardorff 2006; Hojnacki and Kimball 1998, 1999).

Given the importance of legislative allies to interest group success, are some organized interests better able to recruit legislative allies than others? This question has received little attention in the literature. This dissertation offers an original theoretical framework describing both when we should expect some types of interests to generate more legislative allies than others and how interests vary in their effectiveness at mobilizing these allies toward effective legislative advocacy. It then tests these theoretical expectations on variation in group representation during the stage in the legislative process that many scholars have argued is crucial to policy influence, interest representation on legislative committees. The dissertation uncovers pervasive evidence that interests with a presence across more congressional districts stand a better chance of having legislative allies on their key committees. It also reveals that interests with greater amounts of leverage over jobs and economic investment will be better positioned to win more allies on key committees. In addition, interests with a policy agenda that closely overlaps with the jurisdiction of just one committee in Congress are more likely to have legislative allies on their key committees than are interests that have a policy agenda divided across many committee jurisdictions. In short, how groups are distributed across districts, the leverage that interests have over local jobs and economic investment, and how committee jurisdictions align with their policy goals affects their influence in Congress.