Studies of lobbying often draw distinctions between inside lobbying-direct attempts to influence policy through meetings, campaign contributions, and other activities that build and leverage relationships with policymakers-and outside lobbying-activities such as protests, demonstrations, and media strategies that put indirect pressure on policymakers. These studies have found that while all groups increasingly use all available tactics, business and trade associations favor inside lobbying, and citizens' advocacy groups are more likely to engage in outside lobbying. This project reexamines this literature in the context of the recent growth in the use of social media and ask whether existing patterns of lobbying are replicated in the digital environment. We theorize that business and professional groups will be less likely to engage in social media use and, when they do use it, will be more likely to use social media platforms to build and reinforce relationships with policymakers. In contrast, we expect that citizens' advocacy groups will be most likely to engage in an online form of outside lobbying, using social media to inform the public and build grassroots support for their policy agendas. We test these expectations using an original dataset of Twitter and Facebook posts from interest groups. We find that outside lobbying messages are more frequent than inside lobbying messages on social media across all types of groups. Citizens' groups are significantly more likely to engage in social media use overall, and they are more likely to use it for both inside and outside lobbying messages than all other types of groups.

Social media provides an inexpensive way for interest groups to inform and mobilize large audiences, but it is puzzling why organizations would spend time posting about activities like litigation that do not depend on public opinion or mobilization. We argue there are two reasons interest groups post about judicial advocacy on social media. First, organizations provide information about the courts on social media to build credibility and recognition as a trusted source of information. We hypothesize that membership groups will be less likely to use social media in this way than non-membership public interest organizations. Second, organizations use social media to claim credit for activity in the courts in order to increase their public and financial support. We expect that this strategy will be used most frequently by legal organizations. Using an original dataset of millions of tweets and Facebook posts by interest groups, we find support for these expectations.