What influence do lobbyists have on the behavior of interest groups? When representing multiple clients, lobbyists must balance time and credibility constraints with the need to adequately represent each client. We argue that lobbyists resolve these competing incentives by targeting policies that benefit large subsets of their clients, at the cost of a more individualized legislative strategy. We test our theory using an original dataset of intergovernmental lobbying in California. We find high levels of similarity in lobbying behavior among municipalities represented by the same lobbying firm, even when accounting for differences in municipalities’ demographic, fiscal, and geographic characteristics. Using a stacked difference-in-differences design, we find that when these governments change lobbying firms, the structure of their lobbying behavior changes as well. Our findings highlight the role of lobbyists in structuring their clients’ actions and the principal-agent problems inherent in contract lobbying.