Former legislators who lobby, also known as revolving-door lobbyists, exacerbate the effects of resource differences on the relative political influence of various interest groups. These lobbyists command higher fees and represent more clients, and achieve desired policy outcomes more often, than other lobbyists. The value of revolving-door lobbyists, however, is contingent on the continued presence of former colleagues in legislatures. Former legislators achieve influence because of their insider connections and knowledge. Legislative turnover is a consistent, negative predictor of clientele premiums, or how many additional clients revolving-door lobbyists represent than other lobbyists, on average. Other variables display weak or inconsistent effects. This study is the first to examine the value of revolving-door lobbyists in the American states, and corroborates the results of other, recently published studies of revolving-door lobbying. The findings imply that reforms that induce turnover help to level the playing fields of political advocacy for diverse organized interests.